Blades Breaking/ Wood burning - Scroll Saw Woodworking & Crafts Message Board

scroller777 · 07-19-2008, 10:27 AM

Hi, I use a Dewalt 788, I really love using it. ALthough as I was cutting a 1" pice of plywood. It was a puzzle for mykids, I noticed the wood was burning. Unfortunately I went through approx. 8 blads. I did some research and found the Olson blade are very good. So wood burning and breaking blades. Can someone tell me what I might be doing wrong. I can really use one less stressor in my life right now.
Any help would be appreciated. Thank you very much

GrayBeard Phil · 07-19-2008, 12:08 PM

A Full 1 Inch thick Plywood??

WOW!

The glue used to adhere the plywood veneers is usually very hard on the teeth of a scroll saw blade. In addition, with any thickness of wood (solid or manufactured) is the problem of chip (or sawdust) removal. If the geometry of the teeth spacing isn't configured for easy chip removal, then the sawdust gets clogged in the kerf, causing heat, causing the teeth to dull, causing more clogging of the kerf.....(yada, yada, yada)

So, make sure you are using a very high quality blade that have hardened teeth. Olsen blades, unfortunately, do not have the reputation (or if you prefer, 'word-of-mouth') for selling blades with the very hard heat processed teeth on their blades. For your application (1 inch plywood), most styles of Olsen blades will dull quickly, per reputation.

Second make sure you are using at least a double skip tooth blade design. For a full 1 inch plywood, I recommend looking for the widest spacing between the teeth you can find.

Aside: Even with a good extra-hard toothed blade with a skip tooth design, you will still need to cut slowly (rate of feed of the wood past the blade) to give the sawdust plenty of time to escape the kerf while you cut. Not molasses slow, just a bit slower feed-rate than you usually cut at. (blade / motor strokes-per-minute stays the same.)

Just my humble opinion.
Phil

lucky788scroller · 07-20-2008, 04:14 AM

Phil pretty much covered it for you. 1 inch ply shouldnt be to hard to cut providing you are using a good skip tooth blade, even if it is an Olsen blade. Stay away from a reverse tooth blade for thicker wood, especially a plywood because of the glues in it,and by all means feed the wood into the blade slower than normal, saw speed as fast as you can handle.

Gill · 07-20-2008, 08:55 AM

Covering the wood with low-tack masking tape helps to lubricate the blade as it cuts and cools it. I also find that turning the speed of the saw down helps enormously to protect against burning because it allows the sawdust more time to escape and there is less friction from the metal blade against the wood. With thicker material, slower is often (paradoxically) faster.

Gill

scroller777 · 07-21-2008, 07:05 AM

Wow what a difference this makes. I am fairly new to the art. I really love it and am very appreciative of your responses. Thank you for your help. Have a good scroll saw day

turningnut · 07-22-2008, 03:14 AM

Scroller777,

You never mentioned what size or type blade you were using? I was just interested...

Mike

scroller777 · 07-22-2008, 07:08 AM

Hi Mike, the blade I was using was a #7 Olson and and #2 Olson, both skip tooth. I realized that the blade was also touching the side of table as I pushed the wood towards the left. I think that might play a big part in it. I just don't know how to remedy this situation. I think I will ask in post, any ideas? I am using a Dewalt 788

handibunny · 07-22-2008, 10:37 AM

Personally, I hate Olson blades, which I also read were of good quality. I switched to Flying Dutchman blades, and am in love with the reverse and ultra reverse. They are very aggressive cutters, and work very well with thick wood. I've even cut ipe with them, which should not be possible. Mike's Workshop (link on this site) is a great source--good prices and quick delivery. Hope this helps.

Carole

Ramjet · 07-22-2008, 02:59 PM

Re touching the side of the table . Do you have enough tension on your blade ?Roger

Don Williamson · 07-22-2008, 04:39 PM

-Square your blade to the table.
-Adjust the tension to minimize wobble/sideward movement.
-Push the work straight into the blade to reduce and sideward pressure friction on the wood.
I just cut a piece of 3/4 ply to see what would happen; there was no burning so glued two pieces of 3/4 together. I used a Flying Dutchman FD-SR #3 without tapeing the wood with the machine at full speed. Results: clean straight cut with no burning.
Don