Categories
Misc

Changing Your Concrete Saw’s Filter

Of the things you can do to prolong the life of your concrete saw, changing the filters is probably the most important. I’ve seen saw filters get so gummed up with dust that air ends up finding ways around the filter, bringing dust with it, burning up those hard-working 2-strokes.

We like to change ours twice per construction season, or according to hours of use (some saws aren’t used as much as others and only need a filter change once per season). If you own a Partner or similar concrete saw, the first filter will be an oil-impregnated adhesive filter. There might be a temptation to clean this filter out with gasoline and then just soak it in some 30-weight. Don’t! That’s not how the filter was designed to operate, and you’ll just shorten the life of your saw. Pony up the few bucks for the new filter and be done with it.

The second filter is the more traditional accordion paper filter. This is also inexpensive, but I’ve been known to blow it out in a pinch, instead of replacing it. It you try the same, be sure you have your compressor gun on the inside of the filter, shooting out. Blowing from the outside can force dust particles into the paper and reduce the filter’s ability to do it’s job, and can create a situation where dirty air flows past a seal in the filter, instead of through the paper.

While I change filters, I also take a few minutes to disassemble the larger parts of the saw and give them a good cleaning, too. The cooling fan, starter assembly, engine cooling fins and throttle linkages all seem to accumulate a good deal of dust, and can cause problems later if not kept clean. If we were running the concrete saws wet, we’ll take a little more time cleaning, as the dust will likely be hardened onto the body of the saw.

Take these simple steps to care for your concrete saws, and you may get seven or more years out of them, like we do from ours.

Categories
Misc

Safely Running a Paver Saw

Here is a simple fact: blades spinning in a paver saw spin at roughly 5,000 revolutions per minute. If that saw blade throws a diamond segment, it can come flying out of that saw at 100 mph. Pro ball players have a hard time getting out of the way of a 90 mph fastball coming from 60 feet away; you don’t have a chance dodging a piece of diamond coming from 3 feet away. So please, wear your goggles and any head protection you feel appropriate. I know that for the times we’ve run the carbon blades, whether for masonry or metal, I’ve been thankful I had safety glasses on; I’ve seen more than my share of molten carbon fly off the blade and toward my face. I’ve been fortunate enough to not have a diamond segment come in my direction.

My hope is that the above wasn’t really necessary, and that everyone already knows to protect their vision, and hopefully their hearing, too. The issue I wanted to spend more time writing about is running your paver saw dry or wet. I’ve run both our handheld paver saws and our tub saws wet before, but I’ve never liked how water ends up carrying brick dust into the pores of a brick, because it’s almost impossible to wash all the dust out. This has left us with cut brick that looked lighter than uncut brick.

So instead of cutting wet, I prefer to cut dry. But cutting dry presents a new problem: airborne brick dust. This can pose a long-term health problem for employees, and can cause a short-term problem with clients. For our employees I always insist everyone wear a respirator. The disposable filters will last the better part of a construction season, and the mask itself will last several years. A respirator works far better than any of the cheap dust masks you can get at any hardware store; those usually just reroute the airflow around the outside of the mask, allowing the polluted air in at your cheeks. And a respirator only costs about $20 for the mask, and a few dollars for each pair of filters. For clients, be sure to warn them prior to cutting, to close all windows and doors. Many years ago we gave this warning to a client, then began cutting in their paver patio. Unfortunately, they didn’t think the dust would carry from the backyard to the front; brick dust found it’s way over the house, into the garage, and into the windows of their brand-new Ford Explorer. The wife was crying for hours afterward.

If you choose to cut dry, be warned: At a landscape association meeting I attended a few years ago, an OSHA rep told us that because a respirator is not passive protection (meaning the employee has to actually do something to protect himself), they don’t count a respirator as a safety measure against the harm dust from a paver saw can cause. They said that if they were to test your jobsite, they would clip a dust meter to an employee’s shirt to measure the amount of brick dust in the air, regardless of whether the employee was wearing a respirator. When I pressed the issue, he suggested setting up the saws so that the employees were upwind of the dust, to reduce the readings of the dust meters.

Also be sure to wear your hand and foot gear. Some paver saws can vibrate the feeling right out of your hands if you’re running them for a few consecutive hours. Though I’ve never used them, anti-vibe gloves are supposed to absorb a good deal of the vibration without transferring it to your hands. And I can’t say enough about steel-toed boots. If I had known I was going to build this website a few years ago I would have saved some old boots whose steel toes kept a diamond blade from cutting into my non-steel toes. Keeping your blade clean can help to prevent any unfortunate toe incidents, as a clean blade is less likely to grab the piece you’re cutting and wrench the saw from your hands.

Categories
Misc

Masonry Saw Tips, Troubleshooting and Repair

Over the years we’ve broken a few masonry saws. We’ve either been able to fix them or we trashed them; either way we learned something. The articles presented on this page are some of the things we’ve learned about keeping our saws in one piece and running smoothly. Whether it was damage control after a skid steer drove over our Stihl masonry saw, or how a sheared bolt nearly cost us a saw, it’s in here.

We’ve also learned a few things from others in the hardscaping industry, and we’ve done our best to write down those things and share them here.

If there is other general information regarding masonry saws you’d like to see an article about, please let us know by sending us an email at: .

Follow the links in the right column to view our articles on the use and care of masonry saws.

Categories
Misc

Making the Most of your Money Buying Private Label Cutoff Saws

Your first question is probably “What is a private label saw and why should I care?” Good question. Here’s the answer: A private label saw is one that was made by one company but had it’s appearance altered to look like it was made by another company. Sometimes there are small differences in the product, but most often a different color plastic and different stickers are all that make that saw different from the parent brand.

So What?

There are a few reasons this might matter to you when buying a cutoff saw. Let’s say you found a saw for sale by a local construction company going out of business. Or maybe you found one on eBay that’s a steal. Problem is, it’s a brand you don’t know. If the saw won’t run or you need parts (even something as simple as filters), you’ll never find them or the parts will be by special order only, and that bargain will soon start to feel like a 30 pound paperweight. Enter the private label saw. If that steal of a cutoff saw you found was a Speedi-Cut for example, you’d be in luck. As it turns out there are several brand name saws that are all made to the same specs as Speedi-Cut, including Makita, Wacker and Dolmar. No kidding. Need proof? Look at the rotating pictures of saws above. Heck, Dolmar’s website even lists it as being part of the Makita Group, and they use the same numbering system for the manuals, and the manuals are each the same number of pages (92). Case closed.

I can’t quite pin down the cutoff saws from Hilti, Multiquip, Diteq and Husqvarna. Husqvarna and Partner are both owned by Electrolux, and they appear to share some similarities, but are nowhere near identical. But the Hilti, Multiquip and Diteq saws could pass for triplets. Look at the pictures. Look at the specs. For all intents and purposes they are the same saw.

Now I’m not a conspiracy theorist. There are some sensible business reasons to contract to have private label saws made with a different company identity on them. Heck, my wife used to work for a company that made a consumer product for many different private label companies. Making the information about these saws available makes it easier for us as consumers: now we can compare prices on the four versions of the Wacker saw to get the best deal. And we can probably find a parts supplier for one of those brands locally, making buying an unfamiliar brand a lot less risky.

To prove the point, I’m in the process of finding a good deal online for a beat-up cutoff saw by one of the brands listed above, and am going to strip it down to it’s bolts and repair anything that needs repairing using parts from the other private label brands of the same make. It might end up looking like an Eddie Van Halen guitar, but it should hum as good as any other saw.

So if you’re shopping for a saw and want to know which models are alike across brand names, you can use the information below to help in the decision process.

Cutoff Saw Private Label Brands/Models

14″ Makita DPC7301  14″ Dolmar PC-7335  14″ Wacker BTS 1035  Diamond Products Speedi-Cut SC7314

14″ Multiquip HS62  14″ Hilti KC 62-14  14″ Diteq Efco 962TT – A.

 

Update: It even appears that Partner is making a private label saw, using different model names. The interesting thing is, the model names seem to stay the same across private label companies. Zent (China) and Knighton (UK) both use the model name GS350 for their versions of the Partner K700 Active III. The specs are identical for each saw.

I like to share valuable information with visitors when I have the opportunity. During some of my research of these saws I ran across some information on several brands and models of saw. The link is to a portion of the site sponsored by the US Department of Homeland Security, and the information is geared toward people who have to use cutoff saws in rescue situations. But the content is as worthwhile for people in the construction industry as anything else, so feel free to read the reviews of 6 different cutoff saw brands and models.

Categories
Misc

Wacker BTS 1035 Review

Identical Saw Reviews

Because the Wacker BTS 1035 is a private label saw, this review in effect is also a review of the Makita DPC7301, the Dolmar PC-7335 and the Speedi-Cut SC7314, because other than a few differently colored pieces of plastic, these are identical saws. Mechanics at a local construction supply use the parts interchangeably when repairing broken saws.

After having the chance to use the Wacker BTS 1035 on a few projects, I can see why this cutoff saw is being manufactured for so many different brands. Quite a bit of thought has gone into the design of this saw, making it worth comparison shopping against the bigger brand and model cutoff saws like the Partner K700 and Stihl TS400 (which have roughly the same horsepower and identical blade capacity).

One of the first things I noticed was how quiet the saw was. The reduction in noise over our other saws was pretty noticeable. Because I was curious, I had three similar saws running next to each other at idle to see if one wasn’t audible over the others. At idle, the Wacker cutoff saw definitely made the least amount of noise. Once throttled up to full speed the noise level was more comparable to the other saws, but by then you’re usually running it through some brick or a piece of concrete, so noise level isn’t really as relevant.

The next thing I noticed was the saws control of vibration. This is another measure where it’d be nice to have some sort of vibratometer (remove your head from the gutter, please) to provide you with empirical data, but there isn’t one. Or if there is, we don’t have it. What I do know is that my hands stayed extremely steady, whether the saw was running at full speed, buried in a run of pavers, or above the pavers to cool the blade. In the past I’ve had some vibration issues with the Stihl TS400, and if you’re a person that is more susceptible to the damage that can happen to hands and wrists from running heavily vibrating tools, this Wacker concrete cutoff saw would be a good choice for you.

And the vibration control extends to the spinning diamond blade as well. We’ve found that we’re able to make more precise, delicate paver cuts with the Wacker over our Stihl and Partner saws, because vibration is so well controlled over the entire saw. I’m not talking about blade wobble. When I run other saws through a paver to make a sliver cut, many times the bouncing and lateral motion of the saw during the cut will break the cut piece before I can finish the cut. This saw allows me to cut very narrow pieces of brick pavers successfully, which is important if you do a lot of detailed cutting.

Controls on the saw are easily understood and easy to use. The blade guard adjustment provides a comparatively easy way to rotate the guard, and includes a pin-in-slot locking mechanism to prevent the guard from drifting back into it’s previous location.

I also give kudos for the single-switch design, which means fewer moving parts, less things to break, and less time for a beginner to become proficient at using a saw. The Wacker BTS 1035 has a single switch with three positions: Choke, Run and Off. Compare this with Partner saws that have 2 switches, each with two positions, and the Stihl saw, which has 2 switches that each have three possible positions, all to perform the same functions. Putting the kudos aside for a moment, the placement of this switch on the Wacker saw has created a frequent problem of accidentally killing the saw. Often I found myself reaching for the idling saw to throttle up and plunge into a cut only to have a finger or thumb nick the switch and kill the saw.

Of the two other saws I placed side-by-side with it, the Wacker was the longest of the three. The body of the saw was also far bulkier, but overall the top of the handle was the tallest part of this saw and was no taller than the Partner K700. It was surprising to see how much larger this saw appeared, but I believe a large portion of that is a product of the protective plastic shroud cantilevered over the air-cooled cylinder.

The air filtration system is very good, on par with (and similar in design to) Partner saws. Dirty air is pulled through a multi-layered, oil-impregnated filter, then passes through a paper filter before passing through a final clear plastic particulate filter (as a side note I don’t quite understand the need for this final filter, as the sieve size is far larger than anything that should be trying to get past it). The surface area of the oil-laden filter is on the small side, so I wonder if this saw will require more frequent changes of the filter, potentially meaning more down time and greater maintenance costs.

The power output of this saw was adequate. Because I like so many things about the saw I really wanted to brag about the power. Truth be told, as an employee and I were cutting parallel lines through a concrete slab to prep it for removal, his Partner K700, running an identical diamond blade, was cutting through the concrete more quickly than I was with the Wacker. That being said, having a larger fuel tank was nice, as I didn’t have to stop for fuel-ups as often as my guy running the K700 did.

The availability and interchangeability of parts between this saw and the Makita DPC7301, Dolmar PC-7335 and Speedi Cut SC7314 make finding parts for your concrete cutoff saw easier. Ease of use, low noise, low vibration and adequate power make the Wacker BTS 1035 cutoff saw worth your consideration on your next saw purchase.

Wacker BTS 1035 Specs:
Displacement: 73cc
Power: 5.5 hp
Weight: 21.8 lbs
Fuel Capacity: 43 oz
Maximum Speed: 4,300 rpm – spindle
Arbor Size: 1 inch (25.4mm)

Categories
Misc

Stihl TS 400 Cutquik Masonry Saw Review

At the same time I must compliment Stihl and apologize a little bit for this review. The review for the TS 400 is written from my experience using a masonry saw that is eight years old. In looking at the current specs and pictures of the TS 400, I can tell that while there haven’t been huge changes to the design of the saw, I’m not sure there need to be. And the fact that a review can be written about a handheld masonry saw that is eight years old and still running says something about the manufacturer.

Our TS 400 has always been a very reliable saw. Starts cold, continues to run during heavy use on hot days. The saw is one of the lighter ones we have for it’s ability, which means it’s a little easier on the arms and back when cutting in hundreds of lineal feet of brick pavers in a day. However, I do hope that in the more recent versions of the saw, they’ve addressed the vibration issue. A few years ago I spent an entire day cutting some very hard clay pavers, and by the end of the day I couldn’t feel two fingers and the thumb on my right hand. This numbness continued for several days. If there was a silver lining, I had an infected cut on one of those fingers, and was able to scrub it clean with a toothbrush without feeling a thing. But if I had to draw designs with that hand, I’d have been out of commission for awhile.

All at once I both like and dislike the distance between the handles and the blade; having the blade a good deal forward of the handles makes the saw feel a bit safer, moving the cutting action a little further from your hands compared to other saws. However, this also makes for a saw that is less balanced than some of the other masonry saws on the market.

Starting. Hmmm…This one is also a good news, bad news story. The good news is I can predict exactly which pull will start our TS 400, every time, every day, cold or hot. The bad news is, it is almost always pull #13. The first couple years I tried to tweak the carburation settings, but no matter whether the mix was rich or lean, it always took 13 pulls to start. The first 10 pulls were at full choke, with the tenth pull reliably giving me a sputter. Depres the compression release valve again, flip to half-choke, and pull number three at half-choke gets her running.

Air filtration to me is a pleasant surprise. Not using some of the more technologically advanced filtration techniques of other masonry saws, including oil-impregnated filters, the TS 400 relies solely on a foam filter followed by an accordian paper filter like you’d find in most cars. While you’d be inclined to think that this filtration system would not be up to the long-term abuse that the environment that a masonry saw can produce, this saw continues to have clean piston cylinder walls and no blow-by. To me, the results saw everything.

A special note on close cutting: because of the design of the saw and it’s blade guard, the TS 400 allows us to get in tighter against vertical structures when making cuts on horizontal surfaces. This was never made obvious to me until I has to cut away pieces of footings on which rested large posts that supported an outdoor structure. We could snug right up to the posts and cut away large portions of the footing without problems (though the reason we were cutting footings is a long story).

 

Other items of note: The starter cord on Stihl saws is so great that I always buy extra and outfit our other saws with the Stihl “elasto-start” starter cord. Seems to last longer and is easier on the hands and machine when pulling to the full length of the cord. Also, with an arbor size of 20mm, we often need to buy extra plastic rings to slide over the arbor for most of the masonry blades we use.

So if you’re looking for a masonry saw that will allow you to cut in close proximity to a vertical wall, or you’re the type that appreciates the value of a saw that you don’t have to repurchase every few years, and don’t mind some extra pulls when starting or wearing anti-vibe gloves, this might be the perfect saw for you.

Stihl TS 400 Specs:
Displacement: 64cc
Power: 4.4 bhp
Weight (14″): 21.6 lbs
Fuel Capacity: 25 oz
Engine Speed: 9,700 rpm (I believe max spindle speed is aroun 5,400 rpm)
Arbor Size: 20mm

Categories
Misc

Partner K650 Active III Review

The Partner K650 provides lots of portable power for relatively shallow cutting jobs. The K650 is only available as a 12″ blade saw.

Our first K650 Active II was purchased in 2000, and quickly became the workhorse for the majority of the projects we installed, because of it’s power (4.8 horsepower) and it’s light weight (20.7 pounds). Though the K650 only accommodates a 12″ diamond blade, it was perfect for our brick paver installations, as we seldom needed to cut deeper than 2 ¾” (the height of the thickest pavers we install). Different side view of the Partner K650And because most often we’re cutting in paver patios with lots of curves, the smaller blade gives us the best opportunity to cut the pavers where they lay, rather than having to pick them up and move them away from the patio to be cut individually. I’ve even go so far as to try to source some 10″ blades to run on this saw, as they’d give us the ability to cut even tighter curves with this concrete saw. I didn’t find any that would fit this kind of saw (hint to diamond blade manufacturers).

When our K650 Active II grew legs and walked away on us, it was replaced with a K650 Active III and it didn’t miss a beat. A shade lighter than the Active II (19.6 pounds), the Active III has the same power and curve-cutting ability of it’s older brother. On projects where we need to cut a run of pavers 100′ or more, an extra pound or two really make a difference, so the 650 is often the saw that’s grabbed first.

As with the other Partner saws we’ve owned, balance is excellent. The placement of each of the handles relative to the blade offers the user exceptional saw control and we’ve found it to reduce fatigue, as less arm strength is needed to maneuver the saw around the cuts of a patio.

The multiple-stage air filtration system is great, but as I mention in the K700 review, there could be a little better system to anchor the air filtration system to the chassis of the saw, because too often I find the paper filter has had to clean unfiltered air that has somehow gotten past the oil-impregnated filters. This may in part be due to the tendency for these light, powerful saws to vibrate parts loose during use.

While bolts vibrating loose does happen, the transfer of excessive vibration to the user does not. Partner has done an excellent job isolating the handles from the business end of the saw, giving the user a comfortable experience no matter what’s being cut.

It comes equipped for dust-reduction via the water kit, spraying water into the blade guard, catching most of the generated dust and dropping it to the ground. Though this does prevent a lot of dust from clouding the work space and entering your lungs, we never use it, because too often it deposits the fine particles deep into the pores of the brick we’re installing, where it’s impossible to clean out. So we just gear up for the dust, and cut dry. I also think that dry cutting may extend the life of some parts of the saw versus cutting wet (see the troubleshooting article about our K950).

Partner K 650 Active III Specs:
Displacement: 71cc
Power: 4.8 hp
Weight: 19.6 lbs (only available in 12″)
Fuel Capacity: 25.7 oz
Maximum Speed: 5,400 rpm – spindle
Arbor Size: 1 inch (25.4mm)

Categories
Misc

Partner K 700 Active III Review

Partner continues to release saws that are better, stronger, faster. The K700 concrete saw is no exception. We purchased one as a replacement for a K650 that had sprouted legs. Like the rest of the Partner line, this concrete cutter uses oil-impregnated filtersto clean the air headed for combustion. While I like these filters quite a bit, as they can really pull dust out of the air, because there is no firm frame around these filters, I occasionally find that dust-laden air has found it’s way through a tiny ripple in the filter where it didn’t seat perfectly in it’s housing, forcing the accordian paper filter to do more than it’s share of work. But in general, air tends to enter the cylinder very clean and ready to burn.

The power-to-weight ratio of this saw is excellent. With 4.8 horses being generated from a machine that’s just over 20 pounds gives you lots of concrete cutting power in a very portable saw. While you can’t get this saw as close to structures parallel to the blade when trying to cut (i.e. close to a wall when cutting a floor), you can reverse the blade guard to get into tighter spaces. While it appears to work, I’ve heard from people that have done it that it throws the balance of the machine off, making cutting more difficult.

Speaking of balance, this saw has it. The placement of the handles relative to the blade makes this saw comfortable to use in most positions and keeps muscle strain to a minimum. This balance allows you to make more accurate cuts, as you can better control when the saw is dropped into a cut and where it’s cutting. This saw can be run wet or dry, and the included plumbing allows for easy adjustment of water flow.

If this had been a review of our 6-year old, 16″ K950, or even our little K650 that sprouted legs and walk away on us, this review might be a little different. The K950 has always packed a wallop and has been as durable as anything. The K650 saw a few years of daily use, and even ran for a day or so with a puncture in the air filtration system housing. In time the dust that was sucked in during that day caused some cylinder scoring and we started seeing some blow-by, but it was to be expected after that abuse. But I’m not reviewing those saws, I’m reviewing the newer K 700, which hasn’t had as stellar a track record as our previous Partner concrete saws. I’m not sure if I was simply lucky before or unlucky now, or if Partner has made some design changes that have resulted in a less-reliable saw. All I know is, I’ve had to pour an additional $500+ into repairs on a 2-year old saw, when I’ve never had to put more than $20 into parts for any of my saws (aside from filters, plugs and belts).

Our Partner K700 has become a saw that does not seem to like extended use in hot weather. If we’re going to be doing a lot of cutting and it’s hot out, I know we’ll need to bring additional saws, because at some point the K700 will just stop running, and will need a rest of anywhere from an hour to a day before it’ll start again.

We also had a problem with engine seizing. In defense of Partner, the mechanic who repaired our saw claims at some point the saw was run with unmixed fuel. That being said, we have a very small crew, and each man is trained in concrete saw fuel usage, mixing, etc. And the mix can has “Mix” is huge letters on it. In the 8+ years we’ve been running concrete saws, we’ve never had this fuel mix problem happen. So while it is a possibility that unmixed fuel was run in the saw, I’ve also heard from another Partner user who had an identical experience, and he was the only one using the saw, and the piston melted to the cylinder on the first tank of fuel.

We also had a near-miss with a sheared bolt that holds the entire air filtration unit to the saw. Again the mechanic blamed the operators, and again, this has never happened with any of our other saws, Partner or otherwise. I was using the saw one day and after about 40 minutes of use I noticed the housing for the air filters bobbing all over the place. After quickly shutting down the saw I could see that the single bolt holding the housing for the oil and paper filters had sheared where it met the say body, essentially allowing completely unfiltered air into the cylinder for combustion. The mechanic repairing the saw claimed the saw was likely mishandled or dropped, weakening the bolt, which then sheared under normal use. I concede this may be possible, but it just doesn’t seem very likely.

For the negative experiences I describe above, vibration transferred to the operator is minimal for this saw, making all-day cutting a breeze. However, the vibrations sometimes are too much for the saw itself, shaking loose bolts all over the saw. It’s gotten to the point where we have to carry around extra bolts, loctite and zip ties to keep the thing together when out on a job site.

Maybe I’ve had all these problems with our K700 concrete saw because Partner is trying to squeeze every last bit of power out of this tiny package and something has to give. Based on previous experience alone I would still recommend buying a Partner saw; they are light, powerful and easy to handle. But I would also compare it to other saws before writing the check.

Partner K 700 Active III Specs:
Displacement: 71cc
Power: 4.8 hp
Weight: 20.5 lbs
Fuel Capacity: 23.7 oz
Engine Speed: ? rpm (max spindle speed 5,400 rpm)
Arbor Size: 1 inch (25.4mm)

Categories
Misc

Partner K750 [P]review

This isn’t quite a review, because we haven’t run the 750 yet. However, there are enough changes in the K750 that they are worthy talking about, even before we have the chance to test one. Hence the [p]review title. I was at my favorite construction supply store today to pick up some parts for our Partner K950 concrete saw and to rent a hammer drill to punch a hole in a storm drain. While I was there I saw the new Partner K750 brick saw. I noticed a few things of interest while I was there that I’d like to share with you.

The first thing you notice is the form factor of this brick saw – it’s new, aerodynamic curves made it a better looking saw, though I guess the aerodynamics only matter if the saw falls out of your truck while on the highway. Even so, it looks great. Wrapping the body around the shape of the blade guard may have even give the Partner a little more room for filtration or sound dampening.

Switches – the choke switch/lever appears the same as previous models, pull out to choke the engine a little, in to release it. They’ve changed the on/off switch to one that rotates out to turn it off. That makes it more obvious which position it’s in, but for some reason I’m thinking the durability of that switch is now compromised a bit.

One of the touted features of the K750 is the new, automatic decompression valve. No need to press the little blue button anymore. Or is there? I noticed a K750 in a disassembled state waiting to be serviced by the technicians there, and noticed it had the “new” auto-decompression valve, but the brand new saws on the shelf had the old blue button. When I asked the counter guy about it he told me they had gone back to the old compression release valve because they were having problems with the automatic valve. I’m no saw designer, but I was wondering myself about having a rubber hose riding right next to the cooling fins of the cylinder block. Seems to me it wouldn’t take long before that hose was melted through or vibration wore it through. Maybe the problem had nothing to do with that hose, but whatever the problem, these techs are retrofitting every K750 with the older decompression valve when they come in, whether they need it or not.

Exhaust is now ported through the bottom of the muffler, not the top. The same is true for the K700 as well. The muffler does appear bigger, so I’m hopeful that the sound is reduced. Not that this saw is particularly loud; every saw from every brand is. The more that’s done to allow me to hear my kids talking to me when I’m 50 gets two thumbs up in my book.

Visible fuel gauge – I like this feature a lot. It runs vertically alongside the handle of the brick saw. I’m anxious to see if the fuel level is still visible after the clear plastic viewer has been scratched by flopping around in a truck for a year.

T-wrench holder – there’s a little slot that’s been made a part of the water kit, at the switch/valve. However, it’s nothing more than a little holster that will spill the wrench out as soon as the saw is held perpendicular to the ground. Plus, it puts the wrench in the way of the decompression valve. It’s nice that they added this feature, but it’ll need to have some sort of durable (probably metal) latching mechanism before it’ll be useful.

Tighter fit of air filtration system cover to the rest of the system.They must have listened to me! Instead of one or two bolts holding the air filtration system together, there are three. Even better, drawing a line between the three bolt heads forms a triangle (you engineering types will appreciate the strength of the triangle). I expect of all the innovations on this saw, this one will provide the greatest extension of brick saw life, keeping more contaminated air from reaching the combustion chamber.

We have a couple saws that are probably in need of a new home, and I’m interested in replacing them with K750’s to see how they perform.

Partner K 750 Specs:
Displacement: 74cc
Power: 5.0 hp
Weight: 21.4 (14″ version)
Power-to-Weight Ratio: 0.38
Maximum Speed: 5,400 rpm – spindle
Arbor Size: 1 inch (25.4mm)

Categories
Misc

Partner K950 Active Review

You get so much more handheld saw from just two extra little pounds. Our K950 was the second concrete handheld-style saw we ever purchased, after the Stihl TS 400. I had a team of 4 or 5 and we were working on a project that required more than one guy running a handheld saw, so I went to my favorite construction supply store and rented a K950. It felt a little heavy, but as soon as I dropped it into the paver patio we were cutting in, I knew we needed to own one. I clearly remember cutting a run of brick pavers where they laid, roughly 30 feet or so, going through them so quickly and easily that I let out a big “Waahoooo!”

This saw has an outstanding amount of torque. If you’ve ever held a spinning bicycle wheel vertical by holding just one side of the axle, you’ve got the sense of what the torque on this saw is like. If you hold this saw in the air (not in the material you’re cutting) and try to rotate the saw left or right, the saw will work against that effort; that’s how much torque this saw imparts on a big 16″ diamond blade (it’s also available in 14″).

And truth be told, Partner has taken steps to make the K950 handheld a light saw. Where the chassis of the K650K700 and K750 are some sort of metal alloy (most likely aluminum), much of the body of the K950 is plastic. Our K950 is seven years old, so I can say with a little authority that the chassis material has not affected the long-term durability of the saw.

I think one of the reasons the saw ends up being so heavy is having a 16″ diamond blade turning on it – believe it or not the 16″ blade has almost double the surface volume of a 12″ blade, so it’s also almost twice as heavy. Add a full tank of fuel and this saw is getting close to 30 pounds. But for certain cutting jobs, it’s worth it.

We began using the saw for both paver and retaining wall cutting, but have now made it more exclusively a retaining wall and large block cutting machine, as the added power cutting pavers isn’t as much of a benefit as the added weight is a detriment. But it can cut through 6″ retaining wall block without flipping the block over to finish a cut – a huge benefit and time saver with that kind of work. Another reason we don’t use it for pavers is the diameter of the blade. It’s difficult to get a 16″ blade to cut pavers where they lay, in a curved line, without gouging pieces of pavers you don’t want to damage. Even a 12″ blade has trouble with tighter inside curve cuts, but with a 16″ blade it’s just about impossible.

I know what you’re thinking – “Just take off the 16″ diamond blade and put on a 12″ blade, dummy.” The thing is, why bother when we already have at least one other (lighter) saw already outfitted with a 12″ blade. It’s easier just to grab the smaller saw than to fiddle around with changing blades.

Over the last 12 months or so we’ve had problems with shredded belts, and in working to solve the problem have ended up replacing several parts between the crankshaft and the blade. But again, this saw is seven years old, so I’m going to give it a pass for our recent problems, as they seem to be a matter of wear and tear on moving parts on the saw. I know plenty of contractors who only plan for a saw to last a single season, maybe two. Part of that is surely the misuse of the saws in the wrong hands, but part of it is also likely the brand of saw. So I’d say seven years before any major repairs is a pretty good track record.

Overall this has been a very dependable, useful saw for us. Because of it’s power I would not put it in the hands of smaller, weaker employees, or employees with less experience with a handheld concrete saw. It’s ideal for cutting thicker materials (3″-6″), but overkill for cutting pavers or scoring concrete.

Partner K 950 Active Specs:
Displacement: 94cc
Power: 6.1 hp
Weight: 22.7 lbs for the 14″, 24.7 lbs for the 16″
Fuel Capacity: 23.7 oz
Maximum Speed: 5,700 rpm – spindle
Arbor Size: 1 inch (25.4mm)