Stack cutting MDF

[lost_in_endicott]

I'm trying to stack cut a pattern I made for my wife's classroom(20-25 kids). It's 1/8" MDF, and the pattern is pretty simple(a heart shape for Valentine's Day). I tried 5 pieces with painters masking tape wrapped around the edges and the pattern attached with spray adhesive. It did not go well. Mainly, the blade kept grabbing the stack, pulling it up out of my hands. I used a #7 FD SR thinking I would need a larger blade. Should I use a smaller blade? I did slow the saw down to get better control, but the pulling was throwing me off. Maybe I should stack them differently? This is my first time stack cutting. Any suggestions?

[amazingkevin]

I think smaller might help,Its the reverse teeth that pull it out of your hand,hold the work down to control that.

[hawkeye10]

I have said it several times before that I won't make anything out of MDF. I am talking about small projects like clocks and a Santa and his sleigh. If you don't seal it really well painting is a nightmare. Try these guys for some very good scroll wood. Several guys on this forum recommended them and now I do to. Now to your question. I don't have a clue on how to answer it but others will. Now ain't that a bummer.      

 

http://www.ocoochhardwoods.com/

[MrsN]

I cut out 200 hearts for a school, twice. Thanks for helping a school

 

I would probably make a smaller stack, 3 or 4.

 

When stack cutting ornaments I often put a nail or staple in the waste area. If there is a little gap where the pieces aren't flat it can cause trouble.

 

When cutting the hearts out, drill a hole and cut it from the inside. (Rather than cutting from the outside to the pattern line) this will keep your stack strong even on the last cut.

[munzieb]

Not sure if this will work with MDF, especially that thin. I spray contact cement on copy paper, roller it down and then spray the other side of the paper and add the next piece of wood. You could probably stack up to 4 pieces that way with not too much problem cutting. I would be interested to hear if that works for you.

[Bill WIlson]

I would try a smaller blade.  The stack itself shouldn't be the problem, unless it's pulling apart when the blade grabs.  It is functionally little different than  cutting a single layer 5/8" thick.  Also, in MDF, you may not need a reverse tooth blade as much as you would cutting BB ply or hardwood.  The reverse teeth may be grabbing on the upstroke.  If you had something smaller, in a skip tooth configuration, that may be worth a try.

 

If the cut seems to be pulling the stack apart when it grabs, then I would try one of the alternative methods mentioned of securing the stack someplace in the internal waste areas.

 

Good luck.  Hope this helps.

[SCROLLSAW703]

stack cutting can be a feat in itself. And mdf is, imo, is easy to cut, but to stack cut it is another story. First, I wouldn't cut over 3 @ a time, just for the reason you gave. Second, MDF is pressed sawdust. If you try to cut to much of it at one time, your blade will bind, get hot, grab the work piece, & sometimes tear up the project, regardless of the thickness of mdf. ALWAYS start in the center & cut outward.

 

I don't wrap anything I stack cut, & I do quite a bit of it. I use a hot glue gun & glue the corners together. Make sure you keep the glue away from your pieces of the project, because they can be a rascal to get apart w/out breaking them. 

 

Next, try using a skip tooth blade. It'll clean the sawdust out better, & have just as clean of a cut as any other. Also, slow your blade speed down. With mdf, the faster you cut, the hotter your blade will get, & then start binding, breaking blades, etc. Let the blade do the work. You can also use a candle piece, or a small bar of soap to lube the blade. That will help, too. Tension is important as well. Don't over tighten, but a little extra tension than normal is good when cutting mdf. It helps to keep the blade cooler, and keeps your cut line cleaner. 

 

I made a set of gears for my grandson out of mdf. A gear turning assembly. There were 23 gears by the time I was done. I used 1/2" mdf, & stacked four at a time. I used a #3 skip tooth blade, and it turned out great! Turning in mdf can be a hard lesson, too. You aren't able to spin the turn like you can in wood, you have to let the blade make the turn, & stay with it by feed rate. From my experience. It has a tendency to want to break or crumble if you turn to fast. To big of a blade will do the same thing. Keep practicing, & figure out what works best for you. You'll get it, & you'll make your bride mighty proud! hang in there, & enjoy the day. Brad.

Edited September 25, 2016 by SCROLLSAW703

[lost_in_endicott]

Thanks, everyone.

 

I'm going back down to take another whack at it. I'll try a smaller stack and blade. I don't think I have any skip tooth blades, but I do have smaller scroll reverse. The stack wasn't coming apart, it kept pulling up and out of my hands, I think on the up stroke.

 

Ill let you know how it goes.

[Ron Johnson]

A number 3 or 5 blade will correct your problem. I think a number 7 is too agressive.

[stu]

I cut a 100 ornaments every year for local cub scout group and another for grandkids classes back east 1\8 bb stacked 4 all wrapped in painters tape cut with fdur #3 or #5 good luck and thanks for helping keep kids busy with a craft

Stu

[lost_in_endicott]

I finally got back to the scroll saw. I did try a smaller blade(#3 SR) and a smaller stack(3). The results were better, but the scroll reverse blades were burning/ burnishing the edges. I ordered some skip tooth blades, and I finally had time to try them out today. Much better results! A #3 Polar blade, and 3 pieces at a time wrapped the same way as before worked great. I had to learn a different way to get a sharp inside corner because no matter how fast I turned the stack, I kept getting a rounded corner. Once I figured it out, everything went ok.

[Lucky2]

Bill, I stack cut angels out of MDF for a support group, they use them for a memorial service. To stack cut, I glue up five layers of MDF with hot melt glue around the edges. The layers are small squares about 4"x5" or so. They make cutting much easier, as the smaller pieces are easier to handle then a large sheet is. I try to have a bunch of these stacks ready in advance, you never know when you have a few minutes to scroll.

Len

[lost_in_endicott]

I'll have to try that, Len. Someone else mentioned that previously, and I thought it was a neat idea. How thick is the MDF you are using, and what size/type blade do you use?

 

An even better question- how do you handle the dust? I wore a dust mask, but my glasses kept fogging up. It made seeing the pattern kind of tough at times.

[Rockytime]

I also would like to know how to handle the dust. I don't have a dust collection system. I could possible rig up a vacuum cleaner with sort of a funnel like receptor. The vacuum would drive me nuts though.

[NC Scroller]

MDF dust is bad that is why I seldom use it.  If you are using a dust mask and your glasses fog it mean your mask is not fitting properly and moisture is escaping and more importantly dust is entering.  I use a 1/2 half respirator made by 3M.  It seals well and the filters are replaceable.

 

 

 

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