I’m trying to make a sign on 1/2" blond plywood using oramask. The oramask is fraying badly along to top edge of the cut. I’m using a 1/8" bit that came with my Shapeoko XXL pro. I’m guessing that bit is an up-cut bit. Should I be using a down cut bit for this cut?
Yes, a downcut tool such as the #251 or the Amana #46200-K included in some of the Amana sets we sell should yield a better surface finish and should actually push the mask down.
2 Likes
As @WillAdams suggested a down cut would do better. However that would not guarantee that the oramask wont shred up. When you apply the oramaks be sure to use a J roller to press it down well. Just running your hands across it wont really stick it down. An alternative and cheaper method is using Easy Liner Adhesive Shelf Paper I get at Walmart or Lowes. That works as well as oramask and locally available and likely cheaper.
The key is to press it down. Also what might help would be to put a coat or two of Zinnser Universal Sanding Sealer (dewaxed shellac) on the plywood. That stiffens up the plywood to help with the fuzzies.
Depending on what you are going to do to finish your piece I would apply shellac to the carved out bits. This helps keep paint from soaking into the wood and causing a halo effect around the letters. It also helps if you are epoxy filling to keep air bubbles from coming up out of the wood.
That Blondewood they sell at the big box stores is very soft and usually light weight. So it is not your best quality plywood. I am not sure but I think it is old rubber trees that have met the end of their working life and are cut up and made into cheap furniture and plywood.
I second this… I also use these to do painted stencils and the key is ensuring that it’s adhered well to the material. That said, I think I gave up on oromask and others like it because even with down cut bits, it wasn’t cutting well. It’s been a while since I used it, but I’d like to start again because it makes spray painting a lot easier.
Would using a V-carve bit work better in this application
It is not the bit but that the sharpness is key. A new bit will shred less but still shred the mask. There is no perfect solution unfortunately. Not every bit can be brand new. That does not mean it is not sharp but not as sharp as on the first use.
If you look at where the masking shreds it will likely correspond to cross grain areas. When you cut across grain it is unsupported and tends to tear out or fuzz more than when cutting with the grain. So a natural product like wood you cannot just cut along the grain and get a whole project. However hardening the surface with sealers like shellac you will get less fuzz and the wood fibers are better supported when cutting cross grain. Applying the masking down firmly with a j roller gives you the best chance of cutting the masking rather than shredding it. All you can do is the best you can and clean up the mess afterward.
1 Like
I started experimenting with an interesting technique to deal with this. I used the Stingray vinyl cutter to cut the Oramask just a little bit outside of the cut and then removed (or not) the rest of the Oramask. This way, you are not actually cutting the edge of the Oramask.
1 Like
Interesting. More work but gives you a good preview of the cuts as well. When you say “outside” you mean that the oramask would still overhang slightly and the real cutter would trim it or do you mean the other way around? And what is your definition of slightly?
So the definition of “outside” and “inside” is a little ambiguous, I realize. Since I don’t want to cut to the mask, the router will leave a small border between the cut and the Oramask, this border will not be masked, but it is so small that it should not matter. I am still experimenting with it to determine what is the best offset amount.
1 Like
This topic was automatically closed after 30 days. New replies are no longer allowed.