Filling holes in resin

[Egon Spengler]

I'm working on making the Jaguar's Eye of Jumanji from Jumanji Welcome to the Jungle. I've managed to mold and cast my stone but the bottom has a large about of holes in it I'd like to fill in with more resin. The top has smaller pinholes. Is filling them seamlesslessy just a matter of brushing on resin into the holes or do I need to do more prep work like sanding? When all the holes are filled I want to sand and polish the entire thing to a glass like clear finish.

 

[TazMan2000]

I've never tried filling pinholes with resin. I would think the cure time of the resin would be tricky. Your local auto parts store will have a pin hole filler, which is basically very thin filler that should flow easily into the holes and have a bit more work time.
Somebody here mentioned an interesting idea of using photopolymer printing resin to fill in the layer lines of PLA prints. You would paint it over and use a UV light to cure, and I'm wondering if that might work in this case. I wasn't convinced that resin would bond well with PLA, but resin and photopolymer resin might be more compatible.


*Edit* Perhaps brushing in a bit of talcum powder will aide in the resin flowing into the pinholes.

**Edit* sorry. Didnt know if it was clear resin. There are transparent photopolymer resins though.

TazMan2000

 

[Sluis Van Shipyards]

The only thing I've had success with filling pin holes is Mr. Surfacer.

 

[JPH]

any pics?

If it is a clear piece, try to use the same resin that it was originally made from. If very small holes, you can try to pain with XTC but on inspection people will see the different resins.

 

[Mr Mold Maker]

Photos would be a great help.

If you want something glass clear and bubble free, the best way to do that is with a pressure pot. Assuming you don’t have that, even something as simple as a more careful pour and misting some Ease Release 200 on the open pour spout before the resin cures will help reduce bubbles.

If your only option is to work with the cast you’ve got, I would recommend doing your best to get inside any of the airbubbles and scratch it up a little so the new resin has something to bite to. If you don’t get a good bond you could go to cut and buff and pop all of those little resin fillers right out.. ask me how I know..

 

[Duncanator]

Clear casting drives me crazy! Clear resin is tricky to cast and even trickier to fill.

I have successfully filled resin with resin, but there's a challenging balancing act. If you rough up the inside of the bubble so the filling resin has some tooth, you often get a foggy outline of the hole visible in your finished clear part. So I would only recommend scratching up the surface if you were using opaque resin.
On there other hand; if you leave the inside of the bubble smooth, the interface between the casting and the filling resin should be less visible, but I have had the filled bits pop out because they don't bond as well to the smooth surface. This typically happens when the bubble is a open bowl shape, as opposed to a hole that has a slight undercut - (those stay trapped, but are harder to fill).

Either way, when light shines through the clear resin at the right angle, the filled bubbles can sometimes be seen. That may be just fine if you are creating a"natural" crystal look. If you are after perfection, I would recommend doing a fresh casting with a slow setting resin and vacuum degassing it after mixing, and then pressure potting it while it cures in the mold.

I hope this helps. I always hate telling people "you need to buy a bunch of fancy gear to do that right". But clear stuff is hard.