Priming resin parts

[Anthony Kesterton]

I bought a 3D print of the Dragon space capsule recently (before I bought my printer), washed it carefully then primed with Tamiya fine primer from a can. After doing some sanding and filling, I washed again in warm water with some washing up liquid. To my horror, all the primer came off with some light rubbing with a brush. 

The 3D part is a resin SLA printed part. 
 

Any recommendations on primer for these kinds of printed parts?

[Twobad]

I tend to use a cellulose based etch primer. It's a bit aggressive really but it does cling to most things, even brass.

[Anthony Kesterton]

Thanks, will try that. I also had another go after washing the resin part a lot more and leaving it to cure for a lot longer. Will see how it goes. 

[The wooksta V2.0]

I'm using the usual Halfords primer for the aircraft I have on the go.

[spruecutter96]

18 hours ago, The wooksta V2.0 said:

I'm using the usual Halfords primer for the aircraft I have on the go.

I would second that. It's designed to stay stuck to the exterior of cars in all weathers and tempertaures, so some 3D printed material should be no major issue for it. And, bang-for-your-buck, it's cheaper and much easier to find than most modelling products. 

 

Chris. 

Edited September 24, 2021 by spruecutter96
Correcting a typo.

[Anthony Kesterton]

I should have some Halfords primer kicking around here too - will try that next if the Tamiya does not stay on. I was surprised how easily the Tamiya primer came off when I had to wash the parts after priming (they got a bit dusty).  It might be poor curing of the resin or surface grease/stuff.

 

 

[busnproplinerfan]

I don't have much experience yet on 3d printed parts. But for resins I try to use plastic adhesion promoter. It's from bodyshop suppliers. It's used on plastic car parts before any primers go on, seems to have worked so for.

[BKirwan]

I use Mr Surfacer. I have yet to paint over it but notice no real issue when handling the piece. 

[TheBaron]

Can confirm that Alclad's  black primer/microfiller clings happily to Elgoo's standard grey resin.

[The Spadgent]

I have just primed my newly printed parts with Tamiya grey and all seems good. To be fair I never wash with washing up liquid and a brush afterward. Maybe just run under a tap if you need to? 
 

 

[Anthony in NZ]

I have had this issue before with resin parts.  I brought an Automotive 'surface prep' product, I think it is called a wax and grease remover.  Anyway problem solved as my Mr Surfacer now sticks no problem

 

Cheers Anthony

[dcsmax]

I use Stynelrez / One shot / Mr Primer&  Mr Surfacer.

 

Covers the Sirayatech resin beautifully.

[Brandy]

I use Tamiya acrylics as "primer", just to make sure no further work is necessary. That's for any and all types of part, and I've never had any problems so don't see any  need for specialist primers myself.

 

Ian

[Harlequin]

I've had a 3d printer for some time now and have been using Vallejo primer with no problem.

 

If the primer is coming off I'd say it's surface contamination.  When a resin print comes out of the printer it needs to be well washed with the appropriate cleaner, usually isopropyl alcohol.  It then needs to be cured with UV light.

 

Inadequate cleaning or during can leave an almost greasy layer on the surface so you could try giving it a wipe over with some IPA, it shouldn't damage the print at all.

[Pin]

+1 for Mr.Surfacer