[SML] Dissolving foam

[Joe Dunfee]

I am making some Tombstones for "Tilly" based on the book by Peretti.  
This will include both modern and some older ones.

My plan it to use the etching approach, where the lettering is cut out 
of a wide piece of painter's tape, and that is used as a mask for the 
etching.  I came across one tutorial on the Internet that used Spray 
Paint, but I can't find it again.  Specifically, I wanted to know the 
kinds of ingredients to look for on the can, to know it will etch.

I experimented a bit on my own, and tried various solvents on a small 
piece of the blue colored polystyrene available in the big-box hardware 
stores.  I was quite surprised to see that Acetone and Naphtha did 
nothing to the foam.  Though, M.E.K worked quite aggressively.

I am wondering if the foam had a coating, or even if the manufacturer 
may have added something to reduce flammable a bit, and those things 
somehow protected the foam from the Acetone.

I used a small $1 spray bottle,  but found that it was difficult to 
control the depth of the etch. I do recall, many years ago, using spray 
paint on foam, and it etched in a much more controllable way.


Decades ago, it was difficult to find spray paint that didn't dissolve 
polystyrene. Now there are  many that will not dissolve Styrofoam.  Are 
"petroleum distillates" the right stuff to look for?

-- 
-Joe Dunfee
717-203-8670 Cell