Masking nightmare!!!!!!very ugly

[ronbarnes]

I tried a gerber mask on wood and sign foam and while routing they both lifted and wrapped around the bit then threw of all positional measurements. Needless to say my bit ran over places it never should have gone.

QUESTION: What do I use to mask wood and sign board while cutting and painting v-carved letters and such? What do I use for marble and slate? Please help

[zeykr]

I'm assuming you used both a vbit and a endmill to clear the background, did you run the vbit path first? I use an upcut or mortise endmill to get a good clean back to flat areas, but the upcut portion of the endmill will lift and tear the masking. Do the vcarve first to cut the mask. You can then pull the pieces of mask to be hogged out if they are large and wrap around the bit or most the time, you just don't need to worry about it since the vbit delineated and left sharp edges on the areas that need to be masked.

It seems some downcut endmills will cut the mask ok, but upcut almost always lifts and tears it. Have had a couple vbits that did not cut it sharply, but most do fine.

[ronbarnes]

Ken
I have used a v bit in the past but the mask would not stay put. I was wondering what type of mask (part numbers & manufacturers) should I be looking at using???

Thanks for the reply.

Ron

[zeykr]

Ronald,
For smooth finished surfaces such as polyurethane, I use Gerber Mask II.

For rough or unfinished surfaces I use Dr. Crumleys snake oil mask.

Vbits I have good luck with cutting the Gerber mask cleanly are the Hersaf v-bits and I also use a cheap Bosch 9/16 90deg V from Lowes quite a bit. The Hersaf 90v I run at 14K rpm and the Bosch at 15-16K.

[chodges]

Prime your SignFoam first.

We can't get anything (engraver's tape, paint mask, etc.) to stick to SignFoam unless we prime it first.

That's probably why you are having so much trouble.

[jhicks]

Agree on prime 1st but if you are masking, wouldnt you prime and paint 1st, mask then carve, then prime and paint interior of letters?
We use avery mask, standard off cut vinyl, and seem to do ok.
Paint finish and lay down vinyl with a roller/brayer very firmly . Repeat, very firmly before any cutting.

Finally if you are making raw wood with painted interior V letters, you might want to try painting the entire piece after carving a bit deeper, then run it through a wide belt sander with an older belt to remove and sand the top surface off leaving only the painted well of the V carved font.
Get/use a sharp bit. Hersaf is one that we use but Gary Beckwith has a few new V bits you might be interested in for signs as well.

Joes snake oil solution gets rave reviews but we dont do raw wood but I believe whatever Joe tells me and have never regretted it.