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Need Help With Router and Sign Foam


New Member
sign foam on router

I agree with Dennis 19,000 Spindle speed,I use a feed rate as high as 440 ipm when cutting foam.some times will use a finish cut to clean up mill marks when using a longer bit.Foam by far is the eaisest to rout.
Hi Dennis, have not chated with you lately.the remodel is done in the interior,and I have started our largest job ever.We are BUSY,I have work through april.Hope things are going well for you also.I can post some pics of the remodel,but I didn't think that it would interest anybody.

Brian :unclesam:

dennis j

New Member
Hi Brian next time I route Sign Foam I am going to run at your suggested speed I have not run much Sign Foam for the past year with the economy being sluggish around here it has been hard to sell any dimensional signs lately.

I looked at the photos that you posted that is a huge job keep us informed as you progress.

I bet you are glad that the remodel is done I know I am when ever I finish a remodel job. :biggrin:


New Member
I'm new at CNC routing and sign making in general. How would you mount a 4x8x1 1/2 " signfoam. does it need a plywood backer between two posts?
Although some use MDO Plywood as a backer, I prefer to use alumalite. I do not paint the back side of HDU, I clean it well and use Lord adhesive to glue the two together, then set a few stainless screws from behind. As for routing speeds, I will run it as fast as my chip vac will pick it up. Some jobs will allow a full 600 ipm. on cleanouts and V carving, some will not. I keep my spindle @ 19,000 rpm.


New Member
Here's another question. Does anyone prefer priming signfoam before routing or after?
How about masking the surface somehow? Thanks.
I always prime and paint after routing except when I "V" carve inwards. Here is my procedure:
1) Rout job
2) Wash with water/garden hose and let dry
3) Brush prime
4) 2 coats of primer sprayed
5) 2 coats finish

If it's a sign that is placed distantly, I will not prime, just use finish coat. I use nothing but quality exterior grade latex satin paint. I paint all my raised copy with a 3" foam roller.

If the sign has any "v" carvings inward, I will practically finish the sign, cover carving area with paint mask, then re-align sign onto the router and carve through the paint mask into the foam. Apply primer and finish coat into carving and remove paint mask.

As for router bits, I use Gerber V carve bits. I mostly use 60, 90, 120 & 150 degree bits. I know they have a few more sizes, check there website for complete listings.
Good Luck!