[richard3876]

Hi. I'm actually trying to fill in dents of what I believe is a styrofoam tray. And I know little of chemistry. I'd appreciate any help and explanations.

The item is here:

http://homepage.ntlworld.com/richards_internet/Temporary/tray.html

I've been told it's a styrofoam tray.

Anyway, in my experients I want to get a solution to my problem ASAP. So, I'm, hoping you chemistry guys can put me on the right track.

My problem is to fill in those unsightly small dents caused by wear and tear over the years. Now, oil-based modelling clay does work quite well when the dents are deep and sharp-edged. But not well on shallow dents with less defined edges.

Thinking about what fillers might work here is my list of candidates:

* Modelling clay (Like Plastercine): Tried it. Not good with dints that are shallow. Also tried Play Dough, similar results.

* Wood glue: Used it, just dries to nothingness. Not sure if this is PVA or not

* Acrylic glazier's putty:

* Linseed-based glazier's putty:

* Acrylic paint:

* Styrofoam glue:

* PVA white glue:

* Expandable foam in a spray can: Such as from Polyfilla

* Plaster of Paris:

* Silicone rubber:

At the moment I think the best solution might turn out to be painting with acrylic paint, building up the layers until dents are filled.

Seems that we need some adhesion, but nothing that wastes away the fragile styrofoam.

Your help greatly appreciated.  Thank you. Rich

P.S. I've not mentioned much, I know, about chemistry. If someone wants to give some basic chemistry insights, feel free to do so. I like learning stuff. But, as I say, I do not know any real chemistry.

[fledarmus]

You might try acrylic gels - for example, http://www.dickblick.com/products/golden-acrylic-gel-mediums/ They range from thick enough to model, down to thin enough to flow into the shallower dents.

Of course, stick to aqueous solvents. Styrofoam dissolves rapidly in things like acetone, ethyl acetate, and other organic solvents.

[billnotgatez]

the standard way for dry wall construction is to over fill, let dry, and sand.

[richard3876]

I know for sure that styrofoam takes acrylic paint.  Saw a video of that.

Seems then that a good direction to go is with acrylic, just move up on the thickness level.  Gels has been mentioned. I see you can get acrylic paste as well. All I think will have some degree of adhesion and do not, I'm fairly sure, dissolve the styrofoam.

If I get a paste and it works, then I'd paint over the whole styrofoam tray. Sort of encasing it in acrylic. I am actually going to try make a mold of it.