Micro pinhole help

[coyle7717]

Hi all, I have been casting polyurethane shells out of a silicone mould and noticed micro pinnoles in the paint, I am aware they are a defect of the resin (moisture, not degassing) I am going to work on rectifying them with possibly using talc in the mould. But I was wondering if there is a fix to fill these pinholes, I have tried dolphin fine filler putty but I can't seem to get it into the micro pin holes.

 

[19narvik40]

A liquid or aerosol surface primer may work on those. They tend to be thicker than a standard primer and are self settling for the most part. You may still need to sand and add a couple of coats. I would also suggest that unless you are using acrylic paint throughout you avoid an acrylic primer.

 

[Sluis Van Shipyards]

The only thing that has ever worked for me is Gunze Sangyo Mr. Surfacer.

 

[rjenkinsgb]

Possibly vehicle painters "stopper" compound, aka knifing putty? You should be able to get it from any car parts place that sells painting supplies.
It is specifically for filling fine defects and scratches etc.

You can get it in small tubes, or pots/cans etc.

You may need to clean the pinhole with the tip of a tiny drill bit, just a turn by hand, for any compound to key in better.

eg.

Dolphin 1K Stopper Ultra Smooth Acrylic Putty - U-Pol

DOLPHIN 1K Stopper is convenient and ready to use - no hardener required. Perfect for surface imperfections and pinholes, especially last minute situations.

u-pol.com

IMPA 1K Grey Stopper Fine Filler 180g ( Spat O Rapid )

Impa 1K Grey Stopper Finissage Spat O Rapid is a knifing nitroacrylic putty in tube One component fine filler Spot putty used on nitrocombi and

shop.autopaintsbrighton.co.uk

 

[coyle7717]

Thank you everyone for your responses, I've tried surface primer which seems to be doing the trick. I think my issue was that I was putting on filler primer too thick thinking it would fill the holes which was exacerbating the problem when it came to using the gloss paint any divots were showing up. So I've started to use finer coats with the primer and any major pinholes I can fill with spot putty. I also continued to heat the paint can up under warm water to make it flow better .