Using RTV as weight

[Squall67584]

Has anyone used RTV silicone to fill a hollow model to give it some weight?

[Andrew Gorman]

Seems like an expensive way to do it, unless you found some on the street. Plaster , Durhams water putty, gorilla polyurethane glue and old bearings, nuts and bolts have worked well for me in weighting stands. Are you looking for rigidity or just plain road hugging weight?

[Squall67584]

The interior is hollow, but the holes that get to it are kinda small, so I thought about pouring rtv in to give the model some weight to help it balance.

[Ziz]

What kit is it and how much do you need? If you send me the parts, I could pour some resin into them. That might be enough to do it.

[Squall67584]

It's a 3D printed secondary hull that's hollow and only has a hole about 1/4 inch long by 1/8th wide that runs through the neck to the hollow area. Since it's printed as a complete part with the sensor dish area there's no way for me to put a weight in there to make the model more "bottom heavy". I've got the rtv and some resin on hand, but I'd think the resin might warp the part while it's curing.

[Squall67584]

Attack of the dreaded double post

[Joseph Osborn]

I'd use resin and pour in a little at a time to avoid any heat that might warp the part. Maybe even drop some BB's or something along with the resin. Way cheaper than silicone, IMHO.

[dizzyfugu]

Has anyone used RTV silicone to fill a hollow model to give it some weight?

I would stay away from this idea. While you might pump the stuff easily into a kit, I's have concerns with long-time effects. Silicone contains a softener (lots of it, as this is what keeps the stuff flexible and "tight"), and this additive will work on the material it clings to.
It will easily soften, if not dissolve, styrene and probably also work on resin, with a longer time horizon. The effect won't come over night, but will literally destroy the kit from the inside, and it won't be repairable as the material itself deteriorates.

Had a similar case when I filled a radar nose cone of an aircraft kit. One day I wondered if I had used too much varnish, as the radar appeared somehow yellow-ish, but then saw that the nose was actually drooped and had become soft to the touch. Total write-off.

I'd recommend using white glue with some lead beads as weight, or simple stones or plaster - nothing that would react with the kit's basic material, or anything that contains artificial softeners.