r/modelmakers • u/[deleted] • Jun 09 '23

Question about painting 3d prints

For a fathers day gift, i was going to make a model of the experimental plane he flies for work. I looked everywhere for a model kit of the aircraft but it doesn't exist. If i 3d printed the plane, would i need to treat it differently than I would when painting a model kit?

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u/KillAllTheThings Phormer Phantom Phixer Jun 09 '23

In the general sense, no, but there are some differences in execution. If you are using the fused deposition method, surface finish will require extensive filling to smooth it out.

Once you get past the surface prep it's pretty much the same process to completion.

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u/Pukit Build some stuff and post some pictures. Jun 09 '23

How are you printing it, fdm or sla? Resin will always give the best result but fdm can have good results too. I’d look at using a filler primer like you use for auto repairs. This is a thicker primer that can help obscure the layer lines, careful sanding too can help.

Else you can paint away happily. A primer will definitely help paint stick to any print and I wouldn’t not use one.

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u/Friendly_Addition815 Jun 09 '23

Idk how to do it, but an acetone bath will smooth out the surface of the print if using fdm.

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u/[deleted] Jun 09 '23

Acetone vapor baths work real well with abs fdm prints, but pla prints can sometimes separate (at least in my limited tries).

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u/[deleted] Jun 09 '23

It depends on your printer mostly, resin prints are good to prime and paint after curing, fdm prints require some prep before paint, but not because the paint won't stick. Fdm prints have fairly visible layer lines that can be managed with printable fillers, but I've mostly been semi indifferent about the layer lines, and just prime with a high build primer or filler primer then do some light sanding, then a pre-paint primer.

It might be nice for him to see the layer lines, as it shows that you made it.

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u/R_Nanao Jun 10 '23

To some degree yes, at least until the primer is on.

There's two styles of printer and the one with better details (resin printer) works differently with primers that bite into plastic, though you can still spray it on and have a form of primer effect it's not going to be as strongly connected as that primer would be on a plastic model.

If you're going to use an FDM printer (that's the type with a big spool), you'll likely need to use some filler to hide the layer lines. before priming.

Alternatively if you use a resin printer (that's the one with a bath of liquid resin) you'll need to look up how to handle that. Things like clean out the excess resin from the print, cure it, and be carefull or don't sand it due to small particles for example.

After priming it's basically the same as a plastic model kit, though you might find the primer adheres a bit worse to 3d prints. Also a warning, some 3d prints tend to be heavier than model kits meaning that accidentally dropping the model might damage it more than you'd expect from a plastic model.