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Misc

Blade Choices: Which is the Best for your Masonry Saw?

For the work that our company does most often we’re cutting concrete slabs, concrete pavers and block, and clay pavers. For us, there are a few choices to make. The first of which is which type of material of the above will we be cutting with our masonry saws. Many clay pavers tend to be a lot harder than concrete pavers, requiring a different matrix bond. In general, when choosing the bond hardness of your diamond blade, as the hardness of the material you’re cutting increases, the bond hardness of your blade should decrease. The reason for this is when the blade is cutting a softer, more abrasive material, a softer bond would get worn more quickly, releasing the diamond bits too quickly as well, shortening the life of the blade. A harder material may make the matrix seem brittle, breaking apart the diamond bits of a hard matrix.

Another consideration is the grit size of the diamonds. Just like sandpaper, diamond blades with larger grit sizes (diamond pieces) will work through a material more quickly than smaller grit blades. And just like sandpaper, there is a tradeoff between grit size and the finish of the material being cut. Hit a fine piece of cherry with 60 grit sandpaper and it’ll look worse than before you started sanding. Cut glass with a large grit diamond blade and it’ll cut quickly, but it’ll look pretty rough when you’re done. For masonry saws in general, a larger grit blade won’t sacrifice the look of the brick or concrete being cut, and it will save precious labor hours.

You can also choose between masonry saw blades that have great space between segments, allowing for greater cooling. A turbo-segmented blade (T-seg) has small vertical cuts in each of the diamond segments which allow more air to pass through the blade, keeping it cooler and extending it’s life. This also seems to allow the blade to cut a little quicker. At least it seems like it.

There’s also a wide-slot blade that looks more like a ripping blade you might find on a circular saw. More air gets it, keeps the blade cooler. The flipside is, there’s less cutting material on the blade, which could slow the cutting process. Lastly there’s the standard segmented blade. These are a great blade to begin with if you aren’t sure what kind of blades will work best for your masonry cutting tools.

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Misc

Concrete Saw Cutting: Wet or Dry?

If using concrete saws is one of the daily tasks for your company, this decision is an important one. How you cut will have an impact on employee health as well as project quality, and the aesthetics of the materials you’re cutting. I’ll present the pros and cons of each cutting method as I see them, and you can decide which is right for you.

Wet Cutting

Most concrete saws, handheld or otherwise, come stock with a water option. Tub saws include a water pump, handhelds include the plumbing for a household hose connection. And wet cutting has benefits: reduced concrete dust can mean a healthier environment for you and your employees, and less to clean on the structures around you, where airborne dust would normally settle. Diamond blades that run wet also tend to last longer because they stay cooler (even blades designed to run dry can be run wet, and you’ll see a reduction in wear rate). You also won’t have to change the air filters on your concrete saw as often, because the water will keep more of the dust from reaching the air intake.

However, I’ve found that wet cutting can also be very messy. With water flow on a handheld concrete saw adjusted too high, you can end up spraying concrete dust-impregnated water all over your jobsite, creating a much more difficult cleaning job later. Even at lower water flow you can still end up having to take scrub brushes and pressure washers to clean nearby structures that have been coated (and I tell you this from personal experience – the photo above is a project where we spent the better part of a day pressure washing and scrubbing the walls of part the client’s home to get the wetted concrete dust off). With that also comes dumping lots of lubricated dust over the pores of the brick you may be cutting. The water really helps this dust settle deep into the brick, making it nearly impossible to remove (I say “nearly impossible”; someone might be able to do it, but I haven’t figured out how). The result is cut brick that are two shades lighter than uncut brick, and the result of that is usually a long discussion with the client.

Dry Cutting

Dry cutting seems to be less popular in recent years. At a recent jobsite we even had a neighbor call the local health department, claiming we were creating too much dust. The guy from the health department was much more reasonable than the client’s neighbor, but we did end up having to cut wet. Dry cutting can also be messy, dispersing dust far and wide, covering people and structures. However, I’ve found that a few seconds with a leaf blower solves that issue. Dry cutting also presents a hazard for your employees; sucking concrete saw dust into their lungs for years is sure to cause problems down the road.

Without a respirator, the dust from a concrete saw run dry would make it hard to breathe.

However, cutting dry preserves the look of the material you’re cutting. Most all of the dust is sent into the air, leaving only a small bit of dust on the cut material, which again can be cleaned quickly and effectively with a leaf blower. To address the employee hazard, we like to use safety gear that includes eye and hearing protection, but more important for long-term health issues, we use respirators. A simple half-mask respirator with dual filters provide good airflow and a tight seal around the mouth and face, preventing ‘blow by’ of dust around the sides of the mask (this will happen with the cheap paper dust masks you can find at hardware stores). It keeps the lungs of my employees pink, and allows us to provide our clients with a better finished project.

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Misc

Cleaning a Paver Saw Blade

Just like the term “blade” is probably not the most appropriate for a narrow, diamond-impregnated grinding wheel, “cleaning” is also not an accurate term for what we’re doing to our diamond blade. Occasionally when cutting, you’ll find that your handheld paver saw will pull or grab as you’re cutting (sometimes it can almost yank the saw right out of your hands). Often this is the result of a spent blade; look at the segments of the blade, and if there are no diamond pieces left, or the segments that used to be ¼” tall are now 1/16” tall, the blade is spent, and it’s time for a new one. Even if the blade looks like there are still diamond segments in it, like the blade in the foreground in the picture below, the blade is done and it’s time to pony up for a new one.

But sometimes it’s the result of the segments getting gummed up in the material you’re cutting, and just need to be cleaned. But don’t worry – there’s no soap or scrub brushes needed for this cleaning. All that is needed to clean a diamond blade is a piece of cement or concrete (a retaining wall block or concrete paver sometimes works well for this). Running the paver saw at full speed, make a few shallow cuts at a few angles. This will allow the segments to throw off whatever is gumming them up and making them ‘grabby’. I’ve also heard that using a piece of asphalt can also work for cleaning, though I’ve found that asphalt usually gums ours up instead of cleaning them out. About 10-20 seconds of cleaning and your paver saw should be ready to cut like a knife through butter again.

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Misc

The History and Evolution of Diamond Blades

The first diamond blades were invented by a man named Richard Felker during the World War II era. Called “Rimlock” blades, this chemist and pharmacist saw the ineffective metal blades being used for cutting tile and stone and believed there was a better way. When WWII began, Felker had developed several cutoff machines with blades that could handle cutting quartz frequency crystals used in radios and walkie-talkies in the war effort.

A diamond blade isn’t really a blade at all. While it does cut brick and stone, it’s more a grinding wheel than it is a blade; you can’t really cut yourself with it, but you can grind some meat off your foot or hand pretty quickly. When I have new guys working for me, I’d laugh when they’d tell me a blade wasn’t sharp anymore because it wasn’t cutting very well.

The way a diamond blade works is pretty much like a grinding wheel, too. Tiny bits of diamond are impregnated in a metal matrix at the outer edge of the blade. The exposed portion of the diamond is what does the cutting. As the diamonds are worn down, so is the metal matrix, allowing the spent diamond bits to be expelled from the blade, exposing new diamonds beneath to continue cutting.

In more recent years, significant development has been happening to make blades work more quickly and efficiently. One of the more important advancements in this area is improved air flow around the cutting surface and water cooling for portable saws. It’s too easy for masonry saw operators to get overly involved in the cutting of material and forget about allowing the blade to cool. This usually leads to premature blade wear, and big expenses for you. You’ll find more on the topic of blade choice in this section, and more about choosing blades that stay cooler while cutting.

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Misc

Diamond Blade Selection and Use

When we bought our first brick saw, we used carbon blades exclusively. I had a small business, and couldn’t imagine spending $200-300 on a diamond blade, and I could pick up a box of 10 carbon blades for less than $100. That was many years ago, and I recognize that time as an exercise in lost productivity, with inferior blades and the time spent changing them out during a project.

Now I’d like to think we’re diamond blade connoisseurs, and the links on this page will take you to articles about how to choose the right blades for the material you’re cutting, and how to get the most out of the blades you buy. There’s also information about how diamond blades have evolved, from continuous rim to “turbo” segmented. So whether you have a used brick saw or new, tub saw or a walk-behind, you’ll be able to choose and use the right diamond blade.

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:.

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Misc

Compression Tester Assists Troubleshooting Process

On another page I listed off the things I like to look at when considering buying a used cutoff saw. One other tool that’s great to have, both to evaluate used saws and to troubleshoot your own saws is a compression tester. The compression gauge you see pictured here is distributed by Electrolux, which owns both Partner and Husqvarna. It’s a Trisco model G-320HD flex drive compression tester, and the Electrolux part number is 531031686.

The way you use it is pretty simple and straightforward. Remove the spark plug from the saw and screw in the threaded end of the compression tester hose in it’s place. If the cutoff saw you’re testing has a compression relief valve to give easier starts, you’ll need to use it (it won’t affect the test that much). Pull the starter cord 4-6 times, just like you would if you were trying to start the saw (or pull until the reading on the tester stops increasing).

If your saw has compression like it should, the tester should be reading somewhere between 90psi and 115psi, depending on saw brand and model. If the saw has poor compression, it should be pretty obvious. For the cutoff saw I just put a new cylinder and piston into, I could tell it had poor compression before I ever hooked up the tester – pulling the starter cord was way too easy, and there was no “pop” sound like you usually hear when the piston is riding up and down in the cylinder. Hooking up the tester confirmed my concern; the saw was at about 50 psi compression. Not enough for any worthwhile combustion (there were some other problems that kept that saw from running, too. You can read about them in the tutorial).

Poor compression can be a symptom of several things that all have to do with how well the piston and cylinder seal gases in during combustion. Some of the things that can be going wrong with your cut off saw, causing poor compression:

Worn or broken piston rings.
Excessive burning or scoring of the piston and/or cylinder.
A cracked cylinder.

Unfortunately, most often poor compression in a cut off saw is the result of burning or scoring of the piston and cylinder, and they’ll both have to be replaced before the saw will run like it used to. The scoring could have been caused by running a fuel/oil mixture that was too lean on oil, causing the engine to overheat. It also could have been caused by infrequent maintenance/replacement of air filters, allowing dirty air to pass into the combustion chamber. A poor seal between the air filter and it’s housing could also be the cause.

While it’s somewhat unlikely, fuel contaminated with dirt or dust during refueling could also be the cause. This is a bit more unlikely because of the fuel filter in place in all saws – most times the saw will just fail to run properly because the filter is clogged. But the filter may also let small dust and dirt particles through, which get burned in the cylinder and start the scoring process.

Because of the direction of flow of combusted gases in a cutoff saw, you’ll most often find scoring on the piston and cylinder on the exhaust port side of the engine, both on the piston and the cylinder. Occasionally, if the scoring is mainly on the cylinder and is very minor, the cylinder can be cleaned with an abrasive drill bit designed for this purpose. However, most often it’s going to be more cost-effective to just replace cylinder, piston and rings. Then you can be sure the heart of your saw is new, healthy and strong.

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Misc

Price Guide for Final Bid Prices on Cutoff Saws on eBay

We’ve already talked about how to go about bidding in an online auction (linky). Now I want to give you some observational notes I’ve made on the final bid prices for cutoff saw auctions. This isn’t scientific, it’s just the notes I’ve taken when tracking the prices of various brands of saws in various conditions.

Below you’ll find my notes for each of several saw auctions I was watching. Keep in mind that for eBay auctions, the length of time a seller has been a member and their established reputation (as measured by their feedback score) play a role in the final price for a saw. A more trusted seller with a longer track record is going to tend to get a higher price for his stuff than a new seller with no feedback at all.

After the notes you’ll find some general guidelines I follow if I’m going to bid on a saw

  • Stihl TS400 NIB, 14”. 15 bids – $735
  • Stihl TS 400 14”, well used, $286.54, 14 bids
  • Stihl TS 400 14”, 18 bids, $320, used, included new diamond blade
  • Stihl TS 400 14”, $264.99, 13 bids. Used but in working condition

 

  • Partner K700 14” , used, in working order, $248.48, 4 bids
  • Partner K700 14”, from same seller as above, $199.95, 1 bid. Listing mentioned loose handle.
  • Partner K950 ring saw, used, with blade, seller set min bid at $1699.99, got no bids
  • K650, $360.01, 5 bids, used but running
  • Partner K700 14”– Used, looks pretty rough, listed as “runs, but poorly – possible crank seals” – $51
  • K700, w/ daimond blade, 14” $445, 27 bids, used but near new
  • K700 14” NIB, listed at $650, 0 bids, w/ diamond blade
  • 2 DOA K1250’s, $177.50, 10 bids

 

  • WACKER BTS 1035 14″ Used, does not run. $116.49
  • WACKER BTS 1035 L3 14in – $685
  • WACKER BTS 1035 14″ – Used, good working condition – $207.50
  • WACKER BTS 1035 14”. $345 – 20 bids – used, in good condition

 

  • MAKITA 14″ Power Cutter DPC-7311 NIB (New In Box) – $455
  • Makita 7301 14” $237.50, 14 bids, DB, used
  • Makita 6200 157.50, 8 bids, 12”, used

 

  • DOLMAR PC6412 12″$232.50, 4 bids, used, good cond

 

  • HILTI DSKC62 14INCH – Used, very good condition – $300.05

 

  • HUSQVARNA 272K 14 bids, $71, used, not running

When looking at an auction and the items included with the saw, I don’t give more than $50-$75 in added value for a new diamond blade. All too often these are coming from China and you can get your hands on those blades for that price – so don’t think it’s adding a great deal of value to the auction.

For the most part, saws that are 3-5 years old and are no longer running typically get $100-$150. Running saws tend to draw a price between $270 and $400. Newer (but still used) saws will get $450-$550, and “new in box” (NIB) saws tend to garner $550-$680. Shipping shouldn’t run anymore than $40. If it does, deduct that difference from what you’re willing to pay for the saw.

If you see a seller offering an opening bid price of $800 or more, ignore the auction. You can buy just about any saw new from a local dealer for $800-$850, so buying from an unknown person in an unknown place who can’t service your sale just doesn’t seem to make sense. Unless of course you live in a place where there are no local dealers.

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Misc

Buying a Cutoff Saw on eBay, Part 3

The trick to successfully bidding on a cutoff saw to win the auction at the lowest price is resisting the urge. What urge, you ask? The urge to feel comfortable, the urge to win by a large margin. When I watch football I’m usually feeling my best when the Pack is up by three touchdowns halfway through the fourth quarter. It’d be more memorable if it came down to Favre having to orchestrate a last-minute touchdown drive, but that’s not comfortable. And let’s face it, we like comfort.

In terms of cutoff saw bidding on eBay, this means not bidding in bites and nibbles during the auction, slowly ratcheting up the price. What this tends to do is gets everyone involved in the auction excited about winning that item. They’ve researched the seller and the saw and felt comfortable enough to place a bid. Now they’re emotionally invested in the thing. They know how they’re going to use it. They’ve figured out the place in their shop where they’re going to store it. You don’t want to turn up the volume on that. You want to keep everything nice and quiet until the end. It’s been said that success begets success, and the same is true of an auction; more bids seems to bring in even more bids, and no bids seems to scare everyone away. So when you make your bid, you’re only going to make one bid. And you’re only going to place that bid at the very end of the auction. And I mean the very end.

It’s been referred to as “sniping”; like a sniper with a laser scope identifying a target, waiting patiently for the right moment to pull the trigger, then taking the target down with a single, heart-stopping shot. I win auctions by sniping. The name makes it sound like something underhanded, like you’re cheating. It’s not. You’re just waiting until the end of the auction to bid. Nothing wrong with that. What does waiting until the end of the auction do? How about this:

  • It prevents you from getting sucked into the same emotional attachment for the cutoff saw – it’s just business. Treat it that way.
  • It doesn’t give other bidders time to think. Take a look at some of the completed eBay auctions for cutoff saws. You’ll see people bidding 4,5 even 6 or more times on an item. Didn’t they know how much they were willing to spend? Were they thinking that if they bid low early, they’d probably win? It doesn’t make sense to me. Either they aren’t clear on how the process works, or they are emotionally attached to the saw and some amount of logic and reason has left from their decision-making equation. You don’t want someone like that to have time to think about whether they’re willing to spend an extra $5, $10 or $50 on the saw that should be yours. Don’t give them the chance.
  • It’s one less bid on a saw during 99% of the auction, meaning there’s a little bit less demonstrated interest in the item, which might scare a few others away.

All of those things result in the saw’s price staying nice and low, right where it ought to be.

In the top right corner of the window of an auction item you have the opportunity to click on the words “Watch This Item”. I use that so I can keep tabs on auctions, deleting the saved information from “My eBay” if the price gets too high, and saving me the time of having to search for the saw again. Plus, eBay will send me an email when the auction is only a few hours from ending, so I don’t need to keep track of it at all.

After I’ve done my research on the item for sale, I’ll decide what my maximum price is, open a new browser window and navigate to the “Place a Bid” page. I’ll move the process along right up to the point where all I have left to do is click one last button to confirm and place my bid. Then I open a second browser window and navigate to the item again, take note of exactly how much time (minutes and seconds) remains in the auction, then start a stopwatch. When the stopwatch has ticked down to 2-3 seconds remaining in the auction, I click the button in the other browser window to confirm and place the bid.

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Misc

Buying a Cutoff Saw on eBay, Part 2

I’m encouraged to see more and more sellers who perform an appraisal of the saw before they sell it, and mention anything that might be of concern. And if you’re looking to buy a Stihl or Partner cutoff saw, you’ll find plenty to choose from. No need to pin all your hopes on a single saw – if you don’t win that one there’ll be others just like it that’ll follow.

A few last checks and we’re ready to bid: check the shipping and handling charges – a few sellers will try to sneak a bunch of money into that fee (I’ve seen it as high as $150 to ship a cutoff saw that should cost $35 to ship), and once you’ve won the auction, you’re on the hook for that fee, too. Check that the seller will ship to your area (or country), and that they accept payment methods you’re willing/able to use (Paypal, money order, personal check, etc). Now you’re ready to bid. But first, a small economics lesson…

When I first registered as an eBay member in 1999, I thought this was a great way to buy something on the cheap. And back then, when very few people knew about or were comfortable with the idea, it was. But it’s grown so large and accepted that now the normal economic rules of supply and demand apply here. What that means is, if you have something to sell and it’s in high demand relative to how many there are of the item to be found, you’ll probably end up with a high winning bid. On the flip side of that coin, if you’re the buyer, that means you’re probably paying more than what you might expect to, because of the scarcity of the item. At the other end of the spectrum, a cutoff saw that can be found everywhere on eBay during a time when there isn’t high demand can find itself being purchased for pennies on the dollar. Since this is written with the buyer in mind, when at all possible choose a brand and model that is very popular in construction, as the ample supply will dampen demand and tend to keep prices lower. Most often that means you’ll be looking at a Stihl or Partner cutoff saw. Ok, economics lesson over. Let’s bid on a cutoff saw.

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Misc

Buying a Cutoff Saw on eBay

Buying a cutoff saw in an auction format like eBay can be pretty exciting. You don’t know who else is out there, interested in getting that saw. The price is really good right now, but you know that can change at a moment’s notice. There’s an element of uncertainty that makes it a little unnerving.

I’ve been an eBay buyer far more than I’ve been a seller. And there have long been tips and tricks offered on how to win auctions on eBay. Winning them is pretty easy: be the highest bidder. The trick is to be the highest bidder but at the lowest possible price. To do that you have to work against human nature and risk losing the auction item altogether. It just takes a few minutes of research and some nerves. You can do it. But before we talk about how to bid the right way, let’s talk again about security.

Just recently I tried to caution my retired father about jumping too quickly into downloading any software or buying anything online, telling him “This is like the Wild West, Dad; there are rules but they’re pretty loosely enforced, and you could find yourself (or your financial self) full of holes in the blink of an eye.” This is true on eBay, too. If someone doing business on eBay has accumulated enough negative feedback through shady deals enough that it limits the number of bids they get on items (because others are worried about getting burned, too), they can just set up a new account and start from scratch, ready to lure the next unsuspecting victim. You want to take steps to ensure you aren’t that next victim, and you do that by doing some simple checking of the person selling the cutoff saw.

Start your check by looking at how long the seller has been a registered eBay user. If it’s been a short time, this could be a red flag that there were problems in the past. It could also mean the seller just got started selling on eBay. I like buying from people that have been on eBay for at least a year. Next, look at their feedback rating. The percentage of positive feedback and the number of pieces of positive feedback are both important. If they have any negative feedback, read it. If you’re buying a used cutoff saw, was the negative feedback left about the purchase of a similar piece of equipment? Sometimes sellers do well selling small items, but poorly selling larger ones (or sometimes the opposite is true – you don’t know unless you look). Check the positive feedback – are there recent transactions for a cutoff saw? This might tell you this seller handles selling these saws often and can be trusted.

If you’re satisfied with the history of the seller, you should next check the item and it’s description. Read the description carefully – if it’s used, does the seller sound like he’s confident it’s a solid running cutoff saw, or is he trying to distance himself from it with warnings like “sold as is” or the lame “I don’t know if this saw runs or not”. Pull the freakin’ cord, man!