Spray Painting PVC

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freddy1919
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Tue Sep 14, 2010 3:06 pm

I just recently spray painted a design on one of my pvc-made potato guns. I wanted to protect the spray paint and design because it easily scratches off when bumped or dropped on the driveway. I was wondering if i could polyurethane of the spray paint to protect the design? Any other ways to protect the finish? Thanks.
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bighead33
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Tue Sep 14, 2010 4:50 pm

sure i don't think there's any thing wrong with it when used to make Lego's i put polyurethane on them to keep them from falling apart.
some day spudfiles is going to take over the world.
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MrCrowley
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Tue Sep 14, 2010 4:57 pm

I find you have to wait a week for spraypaint to fully cure on PVC. After a week, it doesn't seem to scratch off or flake, it does scratch but the paint doesn't flake off.
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jrrdw
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Tue Sep 14, 2010 4:59 pm

The best way is to use adhesion promoter or Krylon Fusion. The problem with poly's and clear coats is the chamber will expand and contract causing cracks.

If you were using a airbrush or any type of spray gun to paint with you could add a flexing agent/additive that would help avoid cracking...
freddy1919
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Tue Sep 14, 2010 6:27 pm

The Krylon Fusion looks like a good idea for next time, but I've already done the spray painting. As far as the potential cracking, I've only spray painted the barrel and not the chamber. The barrel shouldn't expand and contract right? so poly would be ok then? maybe?

Also, should I use I brush on the poly or by the spray kind?
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Technician1002
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Tue Sep 14, 2010 7:06 pm

Use the spray on kind.

If you don't like the limited color selection of the Fusion paints, I found the primer for plastics is an excellent base for using other brands of paint. I used that for the base on my Mouse Musket. The color layer is appliance paint for the shaded red/black lettering. I did not use a clear coat on top.

The white primer for plastics even works well on ABS. I used 3 shades of blue on my 3 inch ABS barrel on white primer.
The Blue/Red paint on the ABS barrel on the left is applied this way. In contrast the Freon Tank on the far left appears to have been powder coated. Adhesion is poor as evidenced by the many scratches. I did not use primer on it.
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Krylon Fusion by itself does wear off if handled a lot.
Last edited by Technician1002 on Wed Sep 15, 2010 12:45 am, edited 1 time in total.
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chinnerz
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Tue Sep 14, 2010 11:37 pm

sand down the surface, paint, add 10 layers of clear and wait a few days... I use the cheapest paint i can find and after 2+ years, its still good :D

In fact, now that i remember, i also painted my locker's lock in this manner. after 6~ months of rubbing and dropping there are not chips in the paint.
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Wed Sep 15, 2010 6:14 am

freddy1919 wrote:The Krylon Fusion looks like a good idea for next time, but I've already done the spray painting. As far as the potential cracking, I've only spray painted the barrel and not the chamber. The barrel shouldn't expand and contract right? so poly would be ok then? maybe?

Also, should I use I brush on the poly or by the spray kind?
No the barrel should be fine. Any premixed poly or any other protective top coat has a ratio of approx 70% thinner and 30% of the coating that you want. The higher ratio of thinner gives the products shelf life. The 2 part kits you mix yourself have a shelf life of about 2 hours.

Anything premixed will take about a week to fully cure and will cure soft as opposed to the mix it yourself that fully cures in 12 to 36 hours depending on the type and how you mix it, and cures hard as glass.
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