Masks are for Sissies

[ryan_slaback]

I had a big problem today. I was scheduled to present the new Shopbot to my school board and was going to make a desk plaque out of oak for them in front of their very eyes. Problem is... the contact paper I got to use as a mask peeled off when I practiced. So here is what I did...

I planed my blanks an extra 1/32" thick. Then after putting my block in place I zeroed the bit and then lied to the shopbot by adjusting the current Z position from 2.000 after the Z zero to 2.03125 This caused the V carving to be an extra 1/32" deeper than it normally would be. After I engraved the name and Title I spray painted the block and engraving (no mask). When it dried I sent it through the planer engraving side up and it took off the extra paint and material and left the engraving at the right depth and appearance. It worked great and in the future I plan to make this my SOP.

One note, this past summer I installed a shelic cutterhead in our planer which is an index type cutterhead with helical insert placement. This allows for a super smooth cut which is actually a shear. It did not break out an "islands" like this insides of e's and d's. I do not know if this would be as successful with a straight bladed cutterhead.

[mikejohn]

Ryan this works great where the background is laquered wood, probably the best way.
Unfortunately, where you want a painted background you still need to mask


..........Mike

[matt_r]

I agree with Mike on this. Works great if you are using wood backgrouds all the time (and I've used this method before), but if you do MDF signs with painted backgrounds (read - cheaper to have students mess around w/ MDF rather than hardwoods), then you need mask. I'm sure you've seen it mentioned here, but get a real mask, not contact paper. Avery Gerber Mask 2 works very well, and should be readily available at your local sign supply store.

Best of luck with your school board. Hopefully they will see the value in it. I wish they'd had one of these when I was in school.

-Matt

[foamcarver]

Ryan- Another thing to use besides MDF is Trupan, it's just like MDF, but it doesn't have all the bad chemicals in it that MDF has. I'm not sure where you're located but in MN we can get trupan for about 30-35 either 1/2in or 3/4in. Plus I think that trupan cuts a lot cleaner and doesn't leave as much clean up.

Nikki
nicole@foamcarver.com (mailto:nicole@foamcarver.com)

[gerald_d]

"Trupan (http://www.trupan.com.br/)" is the name of a division of a South American company that produces MDF in different densities/weights. There is no case of Trupan versus MDF. The Trupan division of Arauco do Brasil is one of a couple of companies that produce less toxic MDF.