Resin model nightmare (getting rid of bubbles/holes)

Jediguy · Post by **Jediguy** » Sun Feb 13, 2005 9:59 am

Well i've been doing a resin model for a friend and i notice one thing. The bubbles just don't seem to go away. Ive puttied, sanded and sprayed base coat to discover the holes are still there. Then i patched it up and did it again . And new holes somewhere else appear. My god! are all resin kits like this?

OdysseySlipways · Post by **OdysseySlipways** » Sun Feb 13, 2005 10:39 am

is it bubbles or holes?

is it the same little holes showing up or new ones?

sounds like the kit wasn't pressurized when cast.

Jediguy · Post by **Jediguy** » Sun Feb 13, 2005 11:13 am

hmm tiny little holes . Once i sand and clean up one area, theres a new bunch to work on haha. major headache.

Robert S · Post by **Robert S** » Sun Feb 13, 2005 11:22 am

what primer are you using? If it Tamiya or testors you may want to try switching to something in the "sandable" range. By that I mean something like Mr. Surfacer or Krylon sandable. These types of primers have a little more to them and can fill some of these inperfections.

As far as your question about all resin kits being this way the awsers is no but sometimes it happens (even on the best of them)

Also sometimes the air pockets that cause the holes lurk just below the surface and when you sand...

cougar184 · Post by **cougar184** » Sun Feb 13, 2005 11:54 am

what kind of putty are you using?? I use automotive glazing putty to solve this problem. I have found that my other puttys are just dont good enough to solve this problem. as for the primer I would use mr. surfacer. I have not had much luck with Krylon primers however if you can get your hands on some 2 part automotive primer that has always worked good for me too. I work at a autobody shop so the stuff if easy and cheap for me to get a hold of.

ralphee · Post by **ralphee** » Sun Feb 13, 2005 12:42 pm

ive done a lot of figure modelling, anime resin kits come with a lot of airbubbles here in the u.k as we have to put up with 2nd rate recasts most the time, hence the airbubbles, the way i cure this is to use a small ballcutter in the bad areas and refill with miliput superfine, then use a spray putty which is sandable and does a great job at filling the tiny holes in, its time consuming but perseverance is the key, once you have a nice smooth finish a good acrylic primer is used for the basecoat and than finally smoothed with 2000 grit wet n dry.

cobywan · Post by **cobywan** » Sun Feb 13, 2005 2:11 pm

It would help to know what kind of resin you are working on. The Warp brand kits are done in Polyester resin. That is the hard brittle fiberglass resin. They put glass microballoons in the mix and if you sand them they open up. They are very difficult to deal with.

And no. Not all resin kits are like this. There are companies that make resin kits that actually know what they are doing.

Post by **TER-OR** » Sun Feb 13, 2005 2:24 pm

Use a sandable primer like Gunze's Mr. Surfacer.

The object is not to sand down to the model surface, but have a new surface of smooth primer. It may take several coats in some areas.

OdysseySlipways · Post by **OdysseySlipways** » Sun Feb 13, 2005 3:30 pm

cobywan

And no. Not all resin kits are like this. There are companies that make resin kits that actually know what they are doing.

Yes, some of us do try to know what where doing (if not, some of us ask questions on the message boards here).

I normally just buy regular automotive primer either from the local auto store or department store. I do try to check that it is a sandable primer.

big-dog · Post by **big-dog** » Sun Feb 13, 2005 7:19 pm

For tiny bubbles (in the wine) I'd try the Tamiya putty / nail polish remover trick. Wish I'd known about it before I did that Sandman gun. That way you can avoid sanding and thus opening up a fresh batch of bubble, which is what happened to me.

Jediguy · Post by **Jediguy** » Sun Feb 13, 2005 7:47 pm

Im not sure what resin it is but its definitely not polyester resin . And yeah im using gunze base white as i prefer it compared to the mr surfacer. big-dog thanks for the trick! I forgot about that. Maybe i will be able to finish the surface prep by this week afterall haha.

Mark Yungblut · Post by **Mark Yungblut** » Fri Feb 18, 2005 11:00 am

Another thing you could try is to get some Magic Sculpt epoxy putty. It can be thinned with alcohol to the point where it can be rushed on. I would brush a fairly thick layer on, let it sit a while to start to set up then smooth it out with a soft, flat brush. You should be able to get it to a point where little or no sanding is needed. You can also build up layers of the epoxy that way.

Jediguy · Post by **Jediguy** » Mon Feb 21, 2005 10:27 pm

hmm will try that too . Thank you all! my exams are around e corner so well time to put the model aside.Thanks again

Digger1 · Post by **Digger1** » Mon Feb 21, 2005 11:55 pm

I heard somewhere that resin tends to act like wood when it's exposed to certain liquids. When in woodworking class, I learned that dripping water on some small holes and imperfections will actually make them swell so you can sand them off when it dries.

Back to what I heard; soaking resin parts and pieces in degreasing agent can get into the pinholes, make them swell so you won't have to fill them.