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Hopefully I will get my 'Bird sandblasted this coming week (bottom, firewall, trunk pan, and some other areas where I don't have to be concerned with warpage). All the local street rod builders use this guy, and he knows his stuff. I was hoping to get it done earlier when the weather was warmer, but one thing led to another to delay it.

The forecast for the coming week is dry but cool temps in the 60's. I will be using black Omni epoxy for primer, but the tech sheets say nothing about minimum temps for proper out-flow, adhesion, activation, or curing. What would you experienced guys suggest I watch out for to stay out of trouble? The only heat source for the garage is a radiant-type propane job.
 

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Don't spray it at temps lower than 60, and try to preheat your metal before shooting, also make sure the primer itself is not cold. 70-90 degrees would be best for the primer to cure. Epoxy is a slow curing product that is very temperature sensitive, if the temps are low the cure can go dormant. Temperature also effects sprayability as the primer will be thicker when cold and thinner when warm. This is the same for other products like color and clear. If you've got a cold can of primer or paint it can be safely warmed up by setting the can in a bucket of hot water, people have done this for years.
 

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That pretty much confims my suspicions. If it is too cool to shoot the epoxy immediately after blasting, what would be the safest thing to do to prevent flash rust until it is warm enough to shoot?
 

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If you don't have one, try a dehumidifier in your garage. Keeping the moisture down below 50 percent will help plenty. You could treat the metal with Eastwoods "Metal Ready" or "Picklex" (www.picklex.com) metal treatment. Your propane heater will put lots of moisture into the garage since water is the product of combustion, so that may not be good around bare steel. Good luck with your bird!
 

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Firebird, Just to add a bit to what you said about that propane heater. A couple of years ago I had stripped a hood and had it hanging in my shop ready to primer and since it was quite chilly in there I fired up the propane space heater (forced air torpedo type) which I had pointed directly at the hood. I had it a few feet away to prevent getting the hood hot and almost instantly I saw condensation starting to form on the cold metal. I knew water was a byproduct of burning the propane but I just never gave it any thought until I saw the water starting to form on that cold bare metal, amazing how much and how fast. I am sure the metal would dry completely as the area warms up but on sandblasted metal it would seem that flash rust could be problem.
 

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Ditto on the temps for spraying Epoxy.

It has a tendency to fish eye or run badly if you have a low temps.

Lay down a light coat to begin with... once that flashes everywhere on the car you can lay down a little heavier of a coat. Don't think of epoxy as a "filler"primer but more of a protective coat with adheasion. No need to go bonkers and put a bunch on.

Hopefully you'll have a decent day when the temps get back in the low 70's. That'd be Ideal. Make sure you use a chemical degreaser before application of the epoxy.
Hope all your sheet metal work is done so your not grinding/welding on epoxy.
Got the right Idea putting down epoxy first!!! :thumbup: :thumbup:
~Scott
 

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Discussion Starter #7
This is why I am such an avid fan of the site and the forum - I find so much good information from you more experienced guys. I had no idea that the propane heater would produce moisture as it burns, and moisture is the last thing I need after bringing in a freshly blasted body shell. I was thinking that even if it is on the cool side, I could get the blasting done and get her back into the garage and warm it up with the propane, but you guys have kept me from making a big mistake.

According to the weather guys, the temps here are running 10-15 degrees below normal for this time of year, but are supposed to get back up into the 70's next week. Wish me luck, and thanks again.
 

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I was going to ask the same question... about automotive touch up spray paint (done right its very hard to notice) for my Jeep; I'd like it done before winter sets in.
 

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O.K.,

we've talked about Propane Heaters, what about Kerosene? Will they produce some type of Chemical that will harm the finish?
 
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