Edge finish when cutting birch plywood

Hi All,

We cut out a lot of shapes and names from birch plywood. I will generally use a downcut bit for one pass, then a long upcut bit to finish cutting the shape out of 3/4 plywood. The cutting always goes well, but the wood always requires some decent hand cleanup with a file and/or piece of sandpaper. Does any have any suggestions on how to get a clean edge on cutout plywood? Is there such thing as a “sanding bit” that could be run after a cut to try and clean it up on machine rather than by hand?

In a perfect world, Id love to end up with edges that were mirror finish and didnt need any work, but I know that is not realistic. Any suggestions on how you guys get clean plywood edges?

Sorry. Disc sander works best for me. I use both downcut bits and straight cut bits to help eliminate most of the fuzzies. I just cut this project with a Downcut bit that had almost no cleanup. This is cheap sandply from Home Depot

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My main concern is on interior edges on plywood cutout cursive lettering. Its nothing that I can hit with my disc or belt sander. I use the sander wherever possible, everything else gets time consuming hand work. Ill try to get a pic but my phone is busted up.

I use sanding sponges, sandpaper stuck on dowels the Dremel works, depends on the piece

For sanding the faces of small projects I use a cut 36" sanding belt clamped to my work table

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A quick coat of evercoat, then sand.

I picked up one of these:

http://www.brownells.com/gunsmith-tools-supplies/metal-prep-coloring/abrasives/abrasive-rolls-mandrels/4-pre-assembled-sanding-mop-220-grit-sku100016074-73300-154416.aspx

It’s worked great so far but may not get in tight spaces.

Do you happen to have a drill press? I used a 1/2" bolt (fits in my chuck) and taped sand paper to the bolt. Just wrap the sand paper around it and tape top and bottom with electrical tape. Takes about a 30 seconds to set it up. Then, add new sand paper on top and it will get nice and spongy. Remove layers to get the effect you need. You can do this several times and still get into tight areas. Poor man’s spindle sander! You can do the same thing with a corded drill but it would be a lot tougher. I also mounted buffing wheels to bolts and use them in the drill press. That thing get a work out.

This coupled with a bench top belt sander are the only things I use for edge finishing. The belt sander makes quick work of tabs and smooths out your curves. Then to the drill press for finishing.

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Thanks everyone! Im thinking that a long bolt with sandpaper taped to the bolt in a drill might be the ticket for most of the sanding that I mentioned. This wont hit the smallest internal areas as I cut everything with a 1/8 inch bit, but It should get close.

I use a downspiral to break the surface and then an upcut to finish off the cut, ususally beause I need the extra length I have on my upcut bits. Do you think that if I could use the downcut for the whole cut, that is would provide a better finish all the way through, not just on the top edge?

I get good results from a regular 2 flute straight bit.

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Down spiral wont really help the bottom edge (it is trying to push the material out the bottom). I use the same plywood for quite a bit of stuff and theres always sanding, unfortunately. I just my ROS sander and hit it, and then whatever doesnt come off from that I do 1 of 2 things (or both.)

https://www.lowes.com/pd/Shopsmith-Shopsmith-MicroZip-Kit/4747399

or for real small areas (lettering and such)

https://www.amazon.com/Lumberton-12302-Sanding-Sticks-Finishing/dp/B0039ZCQAK/ref=sr_1_4?ie=UTF8&qid=1505611053&sr=8-4&keywords=sandpaper+stick

Hope that helps. I dont think theres really a good way to get rid of the sanding, unfortunately :frowning:

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For really small detail I use finger nail files

I just cut some sanded ply with a straight flute bit for the first time. I’m digging the cut quality as compared to an up cut bit. I’ve yet to try out my downcut bit.

I bought a spindle sander that goes to a 1/2" for getting some of the details. Same basic principle as the drill press but it oscillates up and down.

This method can work. Have a .25" bolt (or rod) as well. And for the inside corners, use this stuff:

https://www.amazon.com/3M-28220SB-UF4-Sandblaster-Flexible-4-5-Inches/dp/B00PPD1VOQ/ref=sr_1_4?ie=UTF8&qid=1505613412&sr=8-4&keywords=3m+sandpaper

As the rod spins, this sand paper stretches into inside corners. You’ll never use a sanding stick again.

You can try a compression spiral bit. They give you a downcut on the top and upcut on the bottom. Never tried them too expensive for me.
https://www.toolstoday.com/p-5638-cnc-solid-carbide-compression-spiral-bits-for-mdflaminate-2-flute.aspx?variantids=6409,0/?gdffi=df1cb0f3ab644accbe5cae9671f148bf&gdfms=597C1B76F0E4493187AB79535E7560A7&gclid=CjwKCAjwl_PNBRBcEiwA4pplRWCjW7tQ-GW07Hy3QLJt9mq8jN2OK5l5L8-sw6JVZiKF4hvNigFAbRoCjA8QAvD_BwE

These only work if you plunge far enough to use both in the same pass. I dont think most x carves would make good use of them :confused:

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I use a straight cut bit for plywood with great results. Very little hand finishing. Once the bit has become dull the results require more hand finishing. I’m going to try out a compression bit too.

Ok, results from my last cutout were a dramatic improvement. I didn’t think my downcut was long enough to make it through the 3/4 plywood but I discovered that it was. So, downcut bit all the way through and then I used a drill bit with sandpaper taped to it to clean it up. Great suggestions all who helped.

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I just tried a Whiteside 1/4" compression bit on 3/4" baltic birch ply. It worked brilliantly and gave me a great finish. I used a 7.5 mm (0.3") step-down at 150 IPM, with spiral ramps to get to 7.5 mm. And your stock needs to be very well secured.

But it is totally doable with the X-Carve.