posted
My local supplier sold me a couple 4x8 sheets of 4lb. density Precision Board for $10.
I want to use it to make some lettering that will hang on an interior wall. I plan to use my cutout tool to do that part.
I tried to use it once before but had a difficult time getting it smooth I guess because it is so soft. I used Coastals FSC88WB Primer/Filler in several coats.
I think I recently read that someone sprays there HDU with 1-shot clear before they prime it to seal the pores. Is this true? Any other suggestions.
This is a freebie project so I am trying to spend as little as possible but I don't want it to look like junk either.
Thanks for any suggestions!
-------------------- Amy Brown Life Skills 101 Private Address
Posts: 3502 | From: Lake Helen, FL, USA | Registered: Feb 2001
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I heard this once upon a once at another sign shop. Their trick to smoothing up urethane board is to take water base wood filler, thin it to almost slurry consistency, and slop it on the board then squegee it with the same gadget we use to smooth vinyl. Let dry, then about all that's left is finish sanding, prime and paint.
Haven't tried it, can't vouch for it, but it sounded reasonable.
FWIW
-------------------- Bill Preston Fly Creek, N.Y. USA
Posts: 943 | From: Fly Creek, N.Y. USA | Registered: Jan 2000
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Amy, get some acrylic gesso at an art supply store. It's the consistency of drywall spackle; you spread it with a trowel. That will fill all the pores and give you a suface that can be sanded smooth. Gesso is used to fill pores on artist's canvas, which would be a lot like the pores on 4lb PB.
-------------------- "A wise man concerns himself with the truth, not with what people believe." - Aristotle
Cam Bortz Finest Kind Signs Pondside Iron works 256 S. Broad St. Pawcatuck, Ct. 06379 "Award winning Signs since 1988" Posts: 3051 | From: Pawcatuck,Connecticut USA | Registered: Nov 1998
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posted
I would say the filler you are using is the best. Actually, I've used a lot of gesso, and would think it to be a little too thin. I know it shrinks as much and is a LOT more expensive than the coastal product...Try, brushing on a coat for first fill. Then another leaving the brushmarks coarse and tall as you can. Then trowel on a coat into the brushmark voids. This can also be done, and maybe better with a roller instead of a brush leaving a heavy stippling effect for thickness. The trowel filling the voids(I use a 5 inch wide one, that fits into the can) will level out the 3rd coat fairly level and thick. One round and cutouts, I use the brush and my fingers for smoothing. I have never found anything better for that. Jack
After re-reading your post, you must have some really porous stuff. I have a freind that sculpts beadboad styrofoam into lifesize characters. He uses a rasp to shape it, and then used the plastic buckets of spackling for fill. It might work well for a base coat, though I have never thought spackling was much of a product for anything but a quick fix. I would expect it to shrink for the next few years. Its more like caulking and not as sandable.
[ February 08, 2002: Message edited by: bronzeo ]
[ February 08, 2002: Message edited by: bronzeo ]
[ February 08, 2002: Message edited by: bronzeo ]
-------------------- "Don't change horses in midstream, unless you spot one with longer legs" bronzeo oti Jack Davis 1410 Main St Joplin, MO 64801 www.imagemakerart.com jack@imagemakerart.com Posts: 1549 | From: Joplin, MO | Registered: Mar 2000
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I've done many projects with low density (6lb or less), and found that polyester resin provided the quickest protection against incidental contact and gave me a glass smooth surface in the shortest possible time.
-------------------- Steve Purcell Purcell Woodcarving & Signmaking Cape Cod, MA
************************** Intelligent Design Is No Accident Posts: 900 | From: Cape Cod, MA | Registered: Oct 1999
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Steve, polyester resin as in fiberglass resin? That sounds like the good course to me. I have worked with 6lb foam exactly one time and it was AWFUL! So fragile we could barely sand it after brushing on water based (coastal) primer - one nick from an edge of the sandpaper would cause big gouges that needed endless refilling and repairs. Something to harden up the foam before even attempting to sand on it is definitely needed. Either that, or just forget about smoothness and go for a very dull finish or even a textured, stippled finish.
SONGPAINTER Original Sign Music by Sign People NOW AVAILABLE on CD and the proceeds go to Letterville's favorite charity! Click Here for Sound Clips! Posts: 1974 | From: Orleans, MA, Cape Cod, USA | Registered: Nov 1998
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Amy, SWEET deal on the foam! How'd you that kinda bargain on a 4x8 sheet? How thick is the sheet?
I use alot of 3lb density foam (cant really call it HDU, 3lb aint HD.. hehe) but I buy it in slabs, 4x8's in thicknesses anywhere from 3" to 48". I use it for sculpting prototypes for my fiberglass work.
Anyway.. my favorite method of filling the surface is polyester (fiberglass) resin with fumed silica mixed in to thicken it up.
You can use as much fumed silica as you need, you make it the consistency you want which can be anywhere from slightly thicker than plain resin to as thick as you could possibly ever want it.
Using this method you can fill the surface quickly and cheaply, and if you've already carved the foam the silica can keep the resin from running off vertical or inclines surfaces.
Just dont kick the resin with too much hardener, that can make it shrink, but polyester resin is very forgiving on its mixing ratio.
You could also use milled fibreglass fibers mixed in with the resin. That has the same thickening affect but makes the mixture much stronger, although a little tougher to sand.
Then there are also fillers with fibers and thickeners already mixed in, like DuraGlass, but I prefer mixing my own to get the right consistency.
Here's the website for a fibeglass supplier in Florida, they have everything you'd need plus great prices on everything.
SONGPAINTER Original Sign Music by Sign People NOW AVAILABLE on CD and the proceeds go to Letterville's favorite charity! Click Here for Sound Clips! Posts: 1974 | From: Orleans, MA, Cape Cod, USA | Registered: Nov 1998
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posted
At the prop & display studio I used to work at, we used Rosco FoamCoat. It is designed for foam carvings, is sandable, durable and doesn't need priming. Much tougher than spackle.
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