Author Topic: Primer with PJ1  (Read 909 times)

Offline Oggers

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Primer with PJ1
« on: March 30, 2022, 10:53:21 AM »
One for Dave maybe....

Can you apply PJ1 onto bare metal? As per previous post, I was thinking of applying a HT (etch?) primer beforehand, but is this truly necessary? What have others done to recoat bare metal barrel/head/cover please?

Offline Laverda Dave

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Re: Primer with PJ1
« Reply #1 on: March 31, 2022, 06:52:07 PM »
As long as the cases and castings are really, really, really clean you do not need to prime them before applying the PJI paint. I had my cases vapour blasted to ensure they were clean and provided a good key for the paint. I don't think you will be able to clean between the fins properly without blasting.

To be honest I'm not sure what would happen if you did use a primer, PJI engine black is designed to be applied without a primer, adding one may actually create an issue.

Important part to remember, you must follow the instructions on the tin and cure the painted parts in the oven for the specified time, make sure the wife is out for the whole day though if using the kitchen oven!!!!! If you fail to cure the paint it will not last long and flake off, you cannot rely on the engine getting hot in use to cure it either. Make sure you cure the barrel with the top of the barrel facing down on the shelf just in case the liner decides to move with the heat!
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Offline AshimotoK0

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Re: Primer with PJ1
« Reply #2 on: March 31, 2022, 09:20:06 PM »
I copied UK Petes method of refinishing Honda bar switches. After removing old anodizing with strong caustic soda then bead blasting, I primed with Clostermanns black acid etch primer and then sprayed with PJ1 satin black and baked in oven at around 125 deg C. turned out really nice. So yes the PJ1 can be applied over acid etch primed alloy.
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Offline Oggers

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Re: Primer with PJ1
« Reply #3 on: April 01, 2022, 11:43:11 AM »
Parts are away for soda blasting. I did think of using a HT etch primer but as you say Dave there appears to be no fundamental reason to do so. Curing  - I'll hang them over a portable gas fire! 

 

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