Help - How to fix tiny pitting

[Hiddenevil]

Hi there

I'm still reasonably new to prop making and was wondering how you guys handle pitting when face with it during a build?

This is the first time i've handled this sort of prop / material before, but i thought it looked a simple enough model to make. However i've spent the last three days doing nothing but sanding it. When it arrived the whole thing looked bumpy, bent and just plain terrible. As i'm sanding it, i'm discovering this tiny pin holes. I'm guessing these are air bubbles from when it was cast.

With the last couple of props i've made, i've used this blue and white, gum type filler that you rub between your fingers to mix. But i think it's a little to thick for these holes. Anyone have any advice? i'm in the UK.

 

[exoray]

Bondo Spot putty or Squadron putty

If needed thin either of them down with a little acetone (real nail polish remover) to make it spread a little easier... Wear some gloves and simply rub in over the surface, sand and prime--- repeat...

 

[Hiddenevil]

Thanks for that, i'll have a look on t'old ebay and see what i can come up with. If i can just get the surface looking flat i shall be happy

 

[exoray]

Thanks for that, i'll have a look on t'old ebay and see what i can come up with. If i can just get the surface looking flat i shall be happy

Skim coat with either of those, sand smooth, hit it with a coat of primer, let dry, wet sand with 200 or 400 grit and repeat if necessary...

Don't try and skip out on the primer, those fillers are not surface or paint ready, you need to lock them down with primer if you want a paint ready smooth surface...

 

[Nobby]

Might be worth giving Milliput Superfine a try

 

[Clutch]

Milliput is messy. Use the Squadron white putty. If you dip your finger in fingernail polish remover and swipe it over the still-wet putty, it will smooth over like glass.

 

[madmanmoe64]

If you can't get hold of bondo products in the U.K then there are alternatives. Isopon is a common brand of car body filler, when people say bondo this is what they mean.
But for really small holes I bought a product called 'Holt's Knifing Putty' which is really good, equivalent to the spot putty mentioned above.

I bought both in 'Halfords', but I'm pretty sure they are on eBay too.

 

[Darth Lars]

Any store that sells plastic models should have spot putty in a tube. There are lots of brands that are just as good -- Squadron is just one.
Bondo is a US brand. When people talk about Bondo, they usually refer to polyester-based auto body filler in general, but within the Bondo brand there is also a spot putty.

Milliput (and other brands of epoxy putty/clay) is quite thick and not easy to use for filling pin holes. If you don't have spot putty at home and have to use Milliput then mix together a small amount of clay and rub it over your workpiece a lot with a lot of water so that putty dissolves and leaves a "foam" -- as if you had rubbed it with soap instead of Milliput. Rub your wet clay over all the pin holes to get the "foam" into them all.

Bubbles at a sharpe edge of a piece of resin can be tricky to fill, even with Milliput. Here I often use a drop of superglue ("CA glue") and sprinkle it with baking soda. The glue will then puff up and become rock hard. The superglue has now created a rough surface that I can smear Milliput or spot putty onto and which it therefore adheres much better to.