first foam

[magic]

This is the first foam sign (or anything else out of foam)

After reading many posts through the search engine I ended up using bondo all around.

My question is, is there a definitive way to seal and smooth the foam? Some prefer West Epoxy and some use water based primer. What's really the best?

[joewino]

HDU does not need to be "sealed" - it has a closed cell structure that keeps moisture (or anything else) from penetrating it. Light on raw HDU is the killer, so it only has to be protected from the sun's ultraviolet light.

By using a higher density foam you eliminate a lot of the fillers that may be needed to achieve a smooth finish, if that is what you desire.

We use FSC-88 WB filler/primer from Coastal Enterprises to achieve a smooth finish. Since a primer isn't really needed, you can just put on several coats of paint - we prefer a water based 100% acrylic like Porter, but any paint will stick to HDU.

It's just the amount of slickness that you prefer. We normally use either a flat or satin paint that does not show imperfections as much as a high gloss.

What is the best? Why, it's the way I do it! That's always the case. http://www.talkshopbot.com/forum/images/icons/icon7.gif

[rej]

how did you attach these to the building?
and how did you make your pattern for the holes ?
thanks

[magic]

No holes, silicone

Cut time 45 minutes

[Big-Tex]

HDU does not need to be "sealed" - it has a closed cell structure that keeps moisture (or anything else) from penetrating it. Light on raw HDU is the killer, so it only has to be protected from the sun's ultraviolet light.

By using a higher density foam you eliminate a lot of the fillers that may be needed to achieve a smooth finish, if that is what you desire.

We use FSC-88 WB filler/primer from Coastal Enterprises to achieve a smooth finish. Since a primer isn't really needed, you can just put on several coats of paint - we prefer a water based 100% acrylic like Porter, but any paint will stick to HDU.

It's just the amount of slickness that you prefer. We normally use either a flat or satin paint that does not show imperfections as much as a high gloss.

What is the best? Why, it's the way I do it! That's always the case. http://www.talkshopbot.com/forum/images/icons/icon7.gif

I use solvent based high build primer.
If job is big enough I buy tinted primer that has color similar to finish coat.
Why solvent? My preference, easy to find, dryes fast betwen coats and sanding. Why tinted? Easy to cover with finish coat. No hoilidays.

Try not to have paint company tint it with regular tint set. Solvent based products need industrial tint set also known as 844. Using regular tint will make primer fail prematurely.


As Mr Chapman stated UV is a HDU killer.

[benchmench]

I agree with Ray Chapman, the FSC-88 WB filler/primer from Coastal Enterprises (located in Orange, CA) produces a great substrate for whatever you want to put on it. They will also send you free samples of their primer if you give them a call.

Check out their video library for some great "how to's" (http://www.precisionboard.com/video.php)

This sign is precision board, FSC-88 primer and 100% Acrylic exterior house paint (Home Depot).

[magic]

I'm takin notes

[magic]

how did you attach these to the building?
and how did you make your pattern for the holes ?
thanks

A better answer on the pattern for the holes.

I drew an an arch that overlapped the artwork by three inches then trimmed out the letters above the arch (and the little segments between, then joined the pieces, then cut a template from cardboard. Once on the ladder I used a sharpie to mark the wall and stuck the letters on with silicone. The double stick tape method held the letters too far away from the surface so I abandoned it and just used the silicone.