Stack cutting problems - Scroll Saw Woodworking & Crafts Message Board

harpone · 07-13-2009, 04:23 PM

I am cutting out the Spielmans' classic alphabet puzzle using a Dewalt saw. I got the plywood wood from a cabinet shop and the stack of 5 pieces I am cutting is approximately 7/8" thick. The letters overlap and I was cutting the whole (first) line of 9 letters starting along the top of the letters. I began with a used Flying Dutchman Polar No.5 blade. I used the highest speed. After cutting 3 or 4 inches (which took awhile) I could smell the wood burning. I decided to finish cutting the tops before changing the blade. It took me an hour to complete the cut along the top of the letters which meant I was half finished with one line! After taking a break I changed to a new fine tooth Vermont American blade I got from the saw's previous owner. The result cutting the bottom: slightly faster cutting but the edges seemed even more burned than the top half of the letters. The burned edges are the biggest problem: sanding them off is a mess and difficult on curved areas.
I am hoping for advice that would make this job easier and faster. Thanks.

unixpro · 07-13-2009, 05:56 PM

I'm not real familiar with the puzzle you're doing, but I've cut like you're describing. For something like that, I would have used either a #5 or a #7 FDSR blade, and I *wouldn't* be going full speed. Slow the thing down to half to start. You're probably burning because you're not able to push the blade through the wood fast enough, so the blade is rubbing and burning. Slow the blade down and let it flow through the wood instead of pushing it. You can also try a blade lubricant, but I've never noticed much difference with those.

markdavd · 07-13-2009, 06:42 PM

I agree with the previous poster - Slow the saw down. Also, the blade is a wear item. As soon as it feels dull, change it. In the long run a dull blade can cost you a lot extra work.

Forester21 · 07-13-2009, 06:55 PM

I have found that plywood dulls a blade quickly! I can cut thicker stacks of most hardwoods easier than the same depth stack of plywood. I think it must have something to do with the layers of glue holding the plywood together.

I would drop it down to 3 layers, and then try the other suggestions given.

T

B Smith · 07-13-2009, 07:37 PM

I agree you should slow down the speed and go to a #7 fdr blade. I would also put packing tape on top to help reduce the friction and help lubricate the blade.

minowevie · 07-13-2009, 08:05 PM

I agree, slow down. cutting at high speed only makes your blades hotter. and once they turn blue. they are gone. it is a patient hobby. just let the blades work for you. cutting a project is not a race any way. it is the end project that you wish to get right. I have found, that cutting with high speed, never got my project done any faster. just my 2 cents. your friend Evie

Jim McDonald · 07-14-2009, 12:43 AM

7/8 of plywood is a tough cut for a #5 and not get burning, especially at higher speeds. As others have said slow down, go up to a #7 reverse or crown tooth and maybe drop the stack at least a 1/4".

Olson makes a stick of something they call blade lube, but I have a feeling that good old beeswax would do just as much.

Bob C · 07-14-2009, 01:33 AM

If you cut down your stack to say 5/8" you can run full speed, it's amazing how much a 1/4" difference in thickness will make. I would suggest FDSR #5 reverse tooth blades as I have great success with these, and you should be able to pick up your speed. Going back and reading your post what kind of plywd are you using anyway?
Have fun
Bob C

harpone · 07-14-2009, 03:05 AM

I think the plywood is birch or cherry; sorry I am not knowledgeable enough to be certain.

harpone · 07-14-2009, 03:42 AM

Thanks to all who took time to share their experience/advice. I will cut slower and try the recommended blades and probably try the wrapping tape too.

07-13-2009, 04:23 PM	#1
harpone Junior Member Join Date: Feb 2009 Posts: 10	Stack cutting problems I am cutting out the Spielmans' classic alphabet puzzle using a Dewalt saw. I got the plywood wood from a cabinet shop and the stack of 5 pieces I am cutting is approximately 7/8" thick. The letters overlap and I was cutting the whole (first) line of 9 letters starting along the top of the letters. I began with a used Flying Dutchman Polar No.5 blade. I used the highest speed. After cutting 3 or 4 inches (which took awhile) I could smell the wood burning. I decided to finish cutting the tops before changing the blade. It took me an hour to complete the cut along the top of the letters which meant I was half finished with one line! After taking a break I changed to a new fine tooth Vermont American blade I got from the saw's previous owner. The result cutting the bottom: slightly faster cutting but the edges seemed even more burned than the top half of the letters. The burned edges are the biggest problem: sanding them off is a mess and difficult on curved areas. I am hoping for advice that would make this job easier and faster. Thanks.

07-13-2009, 06:42 PM	#3
markdavd Member Join Date: Jul 2006 Location: Dallas, Ga Posts: 65	I agree with the previous poster - Slow the saw down. Also, the blade is a wear item. As soon as it feels dull, change it. In the long run a dull blade can cost you a lot extra work. Last edited by markdavd; 07-13-2009 at 09:30 PM.

07-13-2009, 06:55 PM	#4
Forester21 Senior Member Join Date: Jan 2005 Location: Michigan Posts: 1,282	I have found that plywood dulls a blade quickly! I can cut thicker stacks of most hardwoods easier than the same depth stack of plywood. I think it must have something to do with the layers of glue holding the plywood together. I would drop it down to 3 layers, and then try the other suggestions given. T __________________ Theresa http://WoodNGoods.etsy.com http://woodngoods.blogspot.com

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07-13-2009, 05:56 PM	#2
unixpro I need more weekend Join Date: Dec 2006 Location: Greater Seattle Area Posts: 615	I'm not real familiar with the puzzle you're doing, but I've cut like you're describing. For something like that, I would have used either a #5 or a #7 FDSR blade, and I wouldn't be going full speed. Slow the thing down to half to start. You're probably burning because you're not able to push the blade through the wood fast enough, so the blade is rubbing and burning. Slow the blade down and let it flow through the wood instead of pushing it. You can also try a blade lubricant, but I've never noticed much difference with those.

07-13-2009, 07:37 PM	#5
B Smith Senior Member Join Date: Aug 2005 Location: Manitoba, Canada Posts: 150	I agree you should slow down the speed and go to a #7 fdr blade. I would also put packing tape on top to help reduce the friction and help lubricate the blade. __________________ Smitty Dewalt 788

07-13-2009, 08:05 PM	#6
minowevie Senior Member Join Date: Nov 2005 Location: california Posts: 6,398	I agree, slow down. cutting at high speed only makes your blades hotter. and once they turn blue. they are gone. it is a patient hobby. just let the blades work for you. cutting a project is not a race any way. it is the end project that you wish to get right. I have found, that cutting with high speed, never got my project done any faster. just my 2 cents. your friend Evie

07-14-2009, 12:43 AM	#7
Jim McDonald Workin' for the Weekend Join Date: Jun 2008 Location: On the Other Side of the Monitor Posts: 946 Blog Entries: 6	7/8 of plywood is a tough cut for a #5 and not get burning, especially at higher speeds. As others have said slow down, go up to a #7 reverse or crown tooth and maybe drop the stack at least a 1/4". Olson makes a stick of something they call blade lube, but I have a feeling that good old beeswax would do just as much. __________________ Jim Exuberance can be corrected; dullness is incurable. --E. Deters "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."

07-14-2009, 01:33 AM	#8
Bob C Junior Member Join Date: May 2007 Posts: 18	If you cut down your stack to say 5/8" you can run full speed, it's amazing how much a 1/4" difference in thickness will make. I would suggest FDSR #5 reverse tooth blades as I have great success with these, and you should be able to pick up your speed. Going back and reading your post what kind of plywd are you using anyway? Have fun Bob C

07-14-2009, 03:05 AM	#9
harpone Junior Member Join Date: Feb 2009 Posts: 10	I think the plywood is birch or cherry; sorry I am not knowledgeable enough to be certain.

07-14-2009, 03:42 AM	#10
harpone Junior Member Join Date: Feb 2009 Posts: 10	Thanks to all who took time to share their experience/advice. I will cut slower and try the recommended blades and probably try the wrapping tape too.