ByronRC

My Feedback: (2)

I wanna try my hand at making a small plug out of green foam as the base material. Wondering what is used to fill the void, gaps, and dings before sealing? Also should I glass the plug? If so, should I fill then glass or glass than fill? My guess would be fill than glass. After glassing I was thinking of using a high build primer sand smooth before paint. I'm afraid to ask because I'm sure that there are purist, but is there a rattle can option for high build primer and and paint?

speedracerntrixie

My Feedback: (29)

When doing foam plugs I tend to glass then do any body work before paint. If you fill and make the foam perfect before glassing your doing the work twice. As far as primer, do a web search for a primer under the Spray Max name. It is a spray can but has a catalyst. It works pretty well but once mixed you have 24 hours to spray.

ByronRC

My Feedback: (2)

great info. glass then fill. is there a particular filler? I was thinking of Bondo spot putty glaze. will a 3/4 oz glass be sufficient?

speedracerntrixie

My Feedback: (29)

Glass with a few layers of 4 oz sand smooth and then apply a coat of strait resin. The resin will fill any weave and sand fairly easily. Use spot putty only after first coat of primer. Never use Bondo on epoxy.

SCALECRAFT

My Feedback: (13)

Hi All

For a plug.

Florist green foam. The fine cell one that holds water. It can handle Ca. polyester resin, and bondo.

For florists green foam plug:

1) I use Ca to bond pieces to each other if needed to enlarge the piece. . I also use Ca to bond formers to the foam to shape it. It holds.

2) Shape.

3) I use 1 layer .75oz glass to cover: (Why .75oz?.Fast/easy to finish. Because the green water absorbing foam absorbs the resins,and it gets hard. The resin does not stay on top of the foam). Both epoxy and polyester will work on this type of foam. Test a piece first.

4) I use Bondo to fill flaws. Fast. It sticks to anything. Especially my work table and dirty floor.

5) Prime with PEP Boys quick dry high fill primer. Sand/fill//sand/fill............................................ and repeat to your standards.

And remember, it is the mother of all others and it will be fragile and will degrade with time. So, you have to be committed to the end of the process to get a top quality part from your mold.

Steve.

ByronRC

My Feedback: (2)

Scalecraft, Great info. Can't wait to try this. I'll have to locate a Pep BoysLOL

SCALECRAFT

My Feedback: (13)

Or anywhere that has lacquer primer. Fast dry!!

JeffH

My Feedback: (43)

i made a plug with green foam, glassed with two ounce and epoxy since I had it, then did the final body work with polyester filler and laquer spot filler. Primed, then painted with rustoleum black, sanded with 1000-1500-2000 then buffed. I used hair spray for mold release and part popped right off. It was a male plug/final mold since it was an intake duct for an EDF. I even painted white laquer over the hairspray so that the part came out pre painted. Worked awesome.

SCALECRAFT

My Feedback: (13)

By the way, always use a mask or better yet a respirator with this stuff.

I am about to use the green foam for my 104 forward duct sections

Steve

T_om

The filler i have used for a LONG time with foam plugs is a mix of DAP ultra light spackle and Durham's Rock Hard Water Putty. Both are available at big box stores. I get mine from the Lowe's next door to my office. The light spackle is the one that when you pick up the tub from the shelf, it feels empty.

I use a mix of about 70/30 by volume, spackle to Durham's.

Tom

SCALECRAFT

My Feedback: (13)

It's a great mix for the white foams. I use that material as well.

However, the florists green foam as a plug can handle bondo. The cure time is minutes. The sanding is easy. If you can handle the smell. Be outdoors when using it.
Don't get me wrong, I hate bondo, but it makes short work of a plug of green florist foam.

Steve