Hello all,
I am wanting to add text (0.50) tall and 0.062 deep on a sign. I have sealed the stock with polyurethane let dry then applied oramask and ensured there were no bubbles and had proper adhesion.
Using the 60 degree vbit @ 40ipm on 0.50 tall text @ 0.062 the oramask becomes a total mess and some masking on letters such as an lowercase (e) peels off the center of the letter. Summation : the oramask seems to be more trouble than its worth.
Should I use different bit for small text, will that stop the oramask from peeling up and fraying around the edges…
what can I do to help prevent this, I tried to sand it off but its nearly impossible on small text…
Downcut v bits will help.
I’ve been told adhesive shelf paper/liner works better than Oramask. I too find the Oramask not quite sticky enough for fine details. Using a J roller to apply the Oramask and get it really compressed will help too. It’s not just getting the air out, it’s also deforming the adhesive.
Applying a finish to the surface and very fine sanding (400 grit +) also helps
I would recommend applying one or two coats of Zinsser dewaxed shellac (Universal Sanding Sealer) and letting it dry well before applying the Oramask. This will help prevent paint from bleeding outside the carved areas too.
As the other forum member suggested, downcut V-bits work best. I have the 30 and 60 degree V-bits from Cadence Manufacturing and they work very well with Oramask. Usually only minimal cleanup is needed after a carve with a stiff brush. Also, run your V-carve toolpaths twice for the best results.
For some small details, I’ve also used downcut 1/16" and 1/32" flat endmills like the following from Amazon:
I agree with @Tod1d about the adhesive shelf paper. I use the Easy Liner Adhesive Shelf paper I get at Walmart. It is available for many retailers. It is cheaper and better than Oramask.
I have a roll of Oramask collecting dust. I also use the shelf liner under scroll saw projects. The shelf paper keeps the adhesive off the wood underneath I spray on the paper pattern.
I have used shelf liner and had mixed results on fine detail work. You might try doing a profile pass only the thickness of the mask to basically score it and then remove the bits before the rest of the carve.
The Dragknife also works well but may have some offset issues.
I have been using this tape recently on laser projects and it works great there. I haven’t tried it on the CNC but will give that a test.
I can’t see the whole sign, but it may be easier to leave off the Oramask, paint the text, and sand off the overspray.
I like to spray some clear coat on the text before spraying the paint.
I’d also suggest using a 15 or 30-degree bit.
I can’t tell if that’s pine, but Pine is pretty soft and will not carve fine details well.
Poplar, Beech, etc, are good white hardwoods that will handle the fine details better.
The font you pick can also make or break the project. I prefer block letters for fine detail.
