# wandering skillsaw blade



## SE18 (Feb 21, 2008)

It's me again, Mr. Disaster.

I'm ripping 3/4" particle board for my attic floor (so I can move junk up from the garage to then move my tools used to build trains to the vacated space in the garage).


I'm using a Skillsaw with 8" blade (my table saw would be better but the 4x8 sheets are pretty bulky and I didn't want to erect supporting structures or seek the aid of a confederate, not the Southern type).

The blade wanders about a half inch each way and keeps getting stuck and smoking. 


I went slower with the cutting and even erected a fence, but even with the fence (made by a 2x4), the skill saw keeps wandering and I noticed the blade sort of bends, even though I retracted the blade only so it cuts deep enough for the wood.

I'm using a finishing blade that has pretty large teeth (can't recall the # but similar to standard chop saw blades that come with ready to use models). 


I'm thinking I need a special ripping blade or something else.

My neighbor said that particle board has some sort of resins or such embedded that gum things up. 


I miss plywood which smells much better. Seems particle boards are taking over the world.


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## altterrain (Jan 2, 2008)

Two things I can think of - 
Your blade should be set out on about an inch for 3/4 inch material. That will help it from getting stuck. 
If its an old and/or cheap saw, it might be time for a new and better one. 

-Brian


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## Totalwrecker (Feb 26, 2009)

I think the problem is the blade. I'd go with smaller teeth and work slower. The particles are glued toether, without glue they'd have no strength at all. 
Smoking tells me that the blade is loading up and that's what causes the drift. Thin blades flex easier. 
You might try spraying the blade with silcone so the glue doesn't stick as easy. 
Laying and clamping a guide rail can also help, you keep the saw base pressed to it as you go forward. 
John


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## SE18 (Feb 21, 2008)

thanks, I have been using a guide rail and I have been cutting about an inch deep. Time to try a new blade; only other thing I can think of is that the force of the wood is causing it to bind. I've got the 4X8 board up on multiple 2x4s, however to create a good surface cutting area and minimize board flexing; I'll try another blade, it is a bit old.


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## hawkeye2 (Jan 6, 2008)

Once you have cut into the particle board a short distance stop and drive a wedge (ceader shingle, tapered wood, screwdriver) into the kerf. This keeps it from closing up behind the saw and causing all kinds of grief. If you are leting the cut off piece hang out in space clamp a support to the parent piece so that the piece you are ripping off doesn't drop down or sag while you are cutting. Sears used to sell (may still) an item caled, if I remember correctly, a Kerf Keeper which took care of both these problems. 

Particle board has no grain and cuts the same in all directions so there is no need for a ripping blade. The resin used to bind the base material, "sawdust", is hard on blades and they need more frequent sharpening. It has no structural strength and sags or breaks when loaded unless it is supported by a board or plywood sub floor. It is also very dense and adds considerable weight to a structure without adding any strength.


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## wchasr (Jan 2, 2008)

Take it from experience that Particle board (not chip board) is NOT a good idea in an attic. The particle board in my attic would not support my 250 pounds a year ago all on one foot and I dropped that foot thru the Board and the sheet rock in the living room. Now I've got a hole to finish patching in the living room ceiling. (sigh) As Hawkeye said particle board has NO inherent strength. the furniture factory i worked at used a High density PB for making Laminated furniture that was ballistically rated. That was nice stuff but would still degrade over time if left exposed to heat, humidity, and sunlight. 

Chas


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## SE18 (Feb 21, 2008)

Thanks, hawkeye; sounds like a plan


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## SE18 (Feb 21, 2008)

Chas,

Sorry, we were typing same time; incredible experience you have there! WOuld be funny but I'm sure it ain't if you get injured. The 3/4 from Lowe's was advertised as being used for flooring. Seems they used it everywhere in the house for the floors. I'm spacing 22" studs over joists, as there are wiring over the joists I had to bridge with the 2x4s. I'm not getting any wood near the mass of wires nor crowding them and am using wood screws in case I need to get to them later or run more wires


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## Paul Norton (Jan 8, 2008)

When I used to cut my own plywood with a circular saw, I had a sheet of rigid foam that I placed on the floor. The plywood would go over top, and I tacked a strip of hardwood to the plywood as a guide. I could stand or knee on the plywood while cutting and the pieces could not flop about and bind. The foam helped eliminate chipping and deadened the noise of the saw.

Now I have all my sheet materials cut by Home Depot. No noise, no sawdust, and the cuts are clean and square. It also makes it a lot easier to carry and transport. 
If the saw labours, you smell smoke, or the edge of the sheets have black marks; its time for a new blade.


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## wchasr (Jan 2, 2008)

If it is advertised as for flooring then it is likely chip board or strand board. That is made from "chunks" of wood and all glued together under pressure. Particle board is made from sawdust and comes in several grades none of which to my knowledge are suitable for horizontal surfaces unless laminated. For instance like shelving or counter tops.

Chip board is really tough on blades since ther is some "grain" to it but it tend to be all over as the strength there is sort of like plywood where the grains run opposing directions. I'm sure there are better experts on this here than me on this though?

My knowledge came from that furniture factorythat I worked at 20 years ago and is a bit dated now I'm afraid.

The advice about using a small wedge is good too. I've done the same thing when needed on my table saw. Fortunately I had some oak wedges that were scrap material to use from a replica viking slat bed I made for camping. Damn lot of mortises for that let me tell you.

Chas


P.S. I can laugh at falling thru now but only because I was not hurt (and no one else was) and the hole is patched but the textured ceiling still needs fixed, sigh, someday.


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## dltrains (Jan 2, 2008)

As others have stated the particle type boards all use an epoxy resin in the manufacturing process. Last year when I was in the process of ripping a number of cuts and wanting a smooth finish I was using a fine tooth blade and guide. Two blades and about 15 cuts later I went to the local sharpener so I could continue work. Telling him what I was doing he advised a full tooth rip blade which would effectively cut down on the heat build up and still produce a clean cut with minimum chipping and tearout. He was right and I was able to finish the rest of the work without a dull gummy blade and no smoke 

Dave.


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## R.W. Marty (Jan 2, 2008)

You say your using a "Skillsaw", is it a worm drive or a circular saw?
A lot of the less expensive circular saws run the blade shaft directly from the motor shaft and 
develop a lot of wobble real early in life. 

Never seen an 8 inch blade used in a "skillsaw" before
normally a 7 1/4 inch blade is used. Are you using a carbide toothed blade?

Why 3/4 particle board when 7/16 (nominal 1/2 inch) Oriented Strand Board (Chip board used for roof sheeting)
is way less expensive and would be more than adequate for the job.

The saw and blade combination, if correct, should have no problem ripping long strips of the 3/4 particle board.

Better check with the tool store for a better set up.
Good Luck.
Rick Marty


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## K.A.Simpson (Mar 6, 2008)

Also sounds like some of the teeth are missing from the blade. Time to replace blade as it only gets worse and dangerous. Regards from Andrew


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## work4fil (Jan 4, 2008)

I can relate to Mr. Disaster. 

In my youth, I used to be in charge of quality control in a saw mill. I had to supervise cutting of various "mediums." Particleboard, OSB, and medite are all densified wood products and eat saw blades up in a New York minute. One of the things I look for when I get burning or binding is the relationship of the saw blade to the wood. Sometimes the saw will bind due to inadvertent pressure, either from saw position or wood placement. Another thing I look for is if the blade gullets are deep enough to carry and dump sawdust from the kerf. If the gullets are not carrying enough sawdust out of the kerf, the saw will heat up and walk on you. if too deep, the saw may snake on you due lack of support. We used babbit guides for some of our larger saw blades to keep the sawing variations down. The old stand-by is to change saw blades. Now in my old age, I would rather have the help at Home Depot or Lowe's cut it for me there. 

Of course you don't have to thank me, I am rambling on about my halcyon days of yore, when I had more hair and teeth. 

Fil


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## SE18 (Feb 21, 2008)

didn't do any cutting yesterday but will photo the saw and wood tonight; yes, it must be chip wood and yes it must be the 7" and a quarter blade (which has all its teeth). I'll measure the depth of the wood. The skillsaw was a base model from home depot purchased about 9 years ago; don't see it online in the catalog anymore.

When the teeth get dull, should you grind them on a bench grinder? I haven't ever done that. 

The other problem I have is that the nut holding the blade keeps coming loose. It is hard to tighten b/c there's not a 2nd nut to tighten it against; only 1 nut that holds it on and that is it. You have to jam something near the teeth to get it to tighten; kinda hard to explain so i'll take a picture or maybe video it.


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## CHscenic (Jan 2, 2008)

As stated above, particle board is very dense. I would use a 24 tooth carbide blade and set the blade to about 1/16 inch deeper than the thickness of the board. Another option is to cut twice, once with the saw set at a 1/2 inch deep then reset the saw and cut the full depth. As far as the nut coming loose, most often saws have a washer between the nut and blade that is machined so that it fits the shaft without rotating. David Cozzens


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## SE18 (Feb 21, 2008)

This is a great idea; I did in fact, finish some boards by cutting twice. I probably need to install a washer, as you state; I'm thinking metal instead of rubber b/c the rubber may melt.


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## CLRRNG (Sep 26, 2008)

Hello Mr. Disaster,
I have been selling power tools and that type stuff for a long time. Particle board is a very dense product. You need to cut slow. The warping, blade wabble, is caused by the blade heating up. It also puts alot of wear and tear on your saw and continued use will burn it up. The burning smoking material is caused by a dull blade being forced through the material. The slower you cut the more the blade can cool itself. If you need to use the particle board and you have no other material to use I would suggest you cut slowly and use a carbide blade with as many teeth as possible. Let the blade and the saw work at its own pace. 
Also as stated by others particle board is probably the wrong choice for attic storage. It is not very strong across ceiling joists and as I am sure you have found it is very heavy. Ideally it is most suited for cabinet and counter top manufactering. 
A inexpensive alternative would be 7/16" OSB commonly referred to a, wafer board, aspenite. It is a sheathing product used commonly for exterior home construction on the roof and exterior walls and is rated for that purpose. Home Depot and Lowes sell it. 

Good luck 
Glen


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## SE18 (Feb 21, 2008)

thanks Glen

Severe thunderstorms so couldn't do any cutting. Did get some photos. 

Photos show: 

-the curvy nature of the cut on the board; I did use a fence but the blade flexed and yes, it was set 90 deg perpendicular to the wood and about a 16th inch below. I didn't try the wood spreading method yet but you can see the chisel I'm gonna use to follow behind the cutting to ensure wood doesn't bind. 

-yes, the wood IS ¾ inch as I measured it. It is nasty looking wood. The best way to describe it is “head cheese,” if you've ever seen that. 

see photo of access. It is 10 feet high and so so much fun hauling 4x8 thru the access; actually have to cut them smaller to fit. And, if that's not all, it's about 150 degrees up there. And did I mention how much fun it is

see 2 views inside attic; NASTy roofing nails stick out. Penalty for standing up is to get a couple stuck thru your head. You would be hung then from the ceiling with no one to ever find you. Plan to put dry wall up to ensure that doesn't happen (I got bleed marks already on my head) 

there's a long run for the supply railway, which will be used to navigate and carry boxes 

note that the particle board are over 2x4s which are over joists b/c of the mess of romex wiring. I'm using screws so I can gain access if necessary. 

-building shelving on the joists; I'm in the process of hauling out all the junk in the attic to vacuum and lay more flooring and then drywall 

-note there IS a washer on the skillsaw; not just a large washer but also a washer on the bolt; despite this, the nut keeps coming loose despite strong efforts at tightening. AS you tighten it the blade has to be jammed against wood for leverage as there's no back bolt to hold against like most power tools have


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## rkapuaala (Jan 3, 2008)

22 inches on center is too wide for 3/4 inch flooring. The flooring you are using is Oriented Strand Board or OBS and is fine for flooring it the joist are 16 inches on center. More than 16" on center and you should go to 1 1/2 t and g obs. 
I don't understand what you mean by wandering a half inch in one direction or another. That is quite a lot of flex in the blade and would most certainly munch your blade guard that moves up under the top blade cover. 
Use a guide to cut your obs,,, it isn't that tuff of material,,, I use it all the time with my ancient skill 77 without burning blades. 
From the image of the blade, it appears that your arbor hole is too big and the blade has slipped. You need to take the blade off inspect the hole and make sure that the screw fits tightly in the hole so you don't wreck the bearings in the motor.


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## rkapuaala (Jan 3, 2008)

there should be no space between the sides of the hole in the blade and the arbor on your saw.


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## rkapuaala (Jan 3, 2008)

Oh, there should be a blade lock button located somewhere on your saw near the engine cover either front or back. That has to be depressed when you losen or tighten the bolt.


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## R.W. Marty (Jan 2, 2008)

Pretty much what rkapuaala said.
Looks like the bushing in the arbor hole is missing, probably to late to try to save that old circular saw.
Best bet is to dumpster it and go buy a real saw.
Later
Rick Marty


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## CLRRNG (Sep 26, 2008)

Two things I can see from the photos. The blade is not installed correctly and you should not be useing it as it is pictures. Circular saws can be very dangerous and a violant kick back from a faulty blade can cause serious injury. 
Not sure of the make of your saw. On some older circular saws the arbor (motor shaft) had a washer that was shaped like a diamond that was meant to lock into the same shape on the blade. This prevented the blade from slipping on the motor shaft. Most modern carbide blades have a knock out diamond shape that works with circular saws that have that shape. . Check to see if your saw has this feature. If your saw has this feature it is possible that the blade you have installed does not have the matching diamond shape. This would prevent you for getting the most secure pressure on the blade. If it does you will need to purchase a new carbide saw blade with the matching feature. 
Take your saw with you when you goto the hardware store to make sure you are getting the correct blade. 
You should also check to see if the motor shaft is bent. Install a new blade. With the saw unplugged carefully place the saw on its back and expose the blade by retracting the guard. Spin the blade, you should not have any side to side motion at all. If you do the motor shaft is bent and the saw is trash. 

Safety first
Glen


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## Dennis Cherry (Feb 16, 2008)

Are you using a guide? 
Clamp a straight 2 x 4 to the OSB or use the manufactures edge on a piece of plywood. It should be set back about 1" from the actual cut line. Measure from the blade to the outside of the plate on your saw. 

Use a good carbide blade one made to cut the material you are using. Most blades have a listing guide showing what the blade was designed for cutting. 

A anti-vibration washer can be added but it would be over kill for this project. It is usually added for precision cuts making fine furniture.


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## SE18 (Feb 21, 2008)

I think about 3 people have asked if I'm using a guide. I repeat, yes, I'm screwing in a 2 x 4 onto the board and then following it closely with the skillsaw. I notice that it is the blade, not the skillsaw that is curving. I am going slow as well. I am using the baseplate of the skillsaw flush against the guide


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## SteveC (Jan 2, 2008)

SE18

First off, STOP!!![/b]

While others have mentioned it to an extent, the very first thing you've got to do is stop cutting anything until you've corrected two problems. Otherwise you are going to get hurt.

Something is very wrong, the blade retaining bolt should never, repeat *NEVER WORK LOOSE* while in use, second from the picture the *SAW BLADE SHOULD NEVER* change it's relationship to the arbor once locked into position by the retaining bolt & washer.

Both of the above conditions are going to cause you injury if you keep using the saw without correcting them first!

First, if the hole in the center of the saw blade is round it must fit very closely to the arbor (i.e. shaft), no play is allowed. If the arbor (i.e. shaft) is other than round, some are diamond shaped, then the hole in the center of the saw blade must match exactly the shape of the arbor (i.e. once again no play). Some times the saw blade comes with a knock-out center where you can remove it so it'll match the shape of the arbor. If it doesn't then don't use the saw until you get a saw blade that matches the arbor.

If as above stated the hole in the center of the saw blade matches the arbor, and you tighten the blade retaining bolt and washer down tightly, it shouldn't loosen while in use. The bolt should be a right hand thread and the saw blade and arbor are turning in a counter-clockwise direction (i.e. when viewed from the saw blade side) this should cause the retaining bolt to be tightened not loosen.

In looking at a parts list for the Skil #5150-46, there seems to be no integral arbor lock in this model. On some saws you'll find that there is a hole in the upper saw blade guard (i.e. housing, as indicated by the red-headed arrow in the image below) that will align with a hole found in some saw blades (i.e. not the arbor hole in the center), which can be used to hold the blade from rotating by inserting a drill bit or screw driver of the proper diameter through both the saw blade and the housing, when loosening or tightening the retaining bolt. The last recourse is to use a scrap piece of wood to jam the teeth of the blade so it can't turn.


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## SE18 (Feb 21, 2008)

thanks, Steve for the advice. I'm going to stop all work and use the table saw until I get this figured out. It is too bad there's no integral arbor lock in this model. I couldn't find any consumer reports or comments on that saw, which surprises me.


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## 3lphill (Feb 22, 2008)

Good Morning,
Please follow the above advice, having seen the effects of a couple of saw accidents it is some thing you do not want to experienced. I would suggest that you pack up your saw and blade and take them to a commercial repair shop to evaluate the saw and a saw sharpening shop to get the right blade.  There is a lot more to blade geometry than just tooth count. I personally think buying good ($$$) blades and developing a relationship with a sharpening shop will save you money in the long run. And cut better and safer.


Phillip (yes I did try to cut my thumb in half the long way) Timmons


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## SE18 (Feb 21, 2008)

(sheepishly) solved problem; got a blade made for ripping; cuts like hot knife thru butter; no curving blade, straight cut; with a fence I can rip the 8' length of the 3/4" board in a couple seconds


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## Marauderer (Jan 5, 2008)

Wow!!! What a difference a blade makes!!! Hehehe


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## SteveC (Jan 2, 2008)

So long as the retaining bolt has stayed tight and the saw blade is stying concentric to the arbor, then that's great and I'm glad that you're getting done what you need.


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## Les (Feb 11, 2008)

I'm not trying to be a smartass. I have the same problem, nowadays. It's because my wrist and forearm are no longer up to running a heavy saw eight feet through a piece. Fence or not, it 'crawls' around. Cheap blades don't help, either. And from the scuffing, looks like your blade hole might be too big, you need to check that, as someone else has already pointed out. And don't overlook the fact that the saw's nut might be worn, some have a shoulder, some don't. I doubt that's the problem, though. One technique you might try: shove the thing forward into the cut a few inches, back off, make sure the saw's tight against the fence, then shove forward a few more inches, then back up, etc. That's what I do--when I don't have it cut at the lumber yard.









Les


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## Duncan (Jan 2, 2008)

Personal opinion here, but regardless of your current success, I would be inclined to dispose of that saw... 
That picture of what looked like a loose blade was vewwy, vewwy scawwy... 
If you have any plans to do much more in the way of "portable wood shortening", strongly consider selling it, giving it away, or see how far you can chuck it (ala olympic hammer throw). 
A worm drive saw (like a Skil model 77) is so much safer, given that your hand is not directly over the motor axis. This eliminates much of the binding and kick back experienced in cutting sheet goods with a regular "home owners" circular saw. 
I've had my model 77 for over 30 years now, and it still runs flawlessly. 
Again, just my opinion...


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## neals645 (Apr 7, 2008)

By all means stop using that saw, but don't throw it away. If you completely disassemble it you will have some great parts to use for a flatcar load!


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