Quote:
Originally Posted by Bill Douglas
Impressive work Chris. What is your choice in epoxy primer. And are you going to do a phosphoric acid wash beforehand?
LOL I'll copy you.
|
SPI (Southern Polyurethanes) makes the best epoxy primer on the market IMO. Glasurit and others make a good epoxy, but none of them build well nor do they sand well. And they are hideously expensive. SPI has outstanding corrosion protection, flexibility, and adhesion, in addition to being able to build, and it sands nicely. On this job I will use no other primer other than the epoxy. Doing so will greatly cut down on the chipping that happens when using a 2K urethane or polyester primer. It can also be reduced and used as a sealer.
No I have no plans for that. I try to use phos/acid treatments as little as possible. I would rather media blast for a number of reasons.
As for phosphoric acid treatments, if you have to use one you need to neutralize it before you apply epoxy, otherwise the epoxy will not adhere. How you do that is when you have finsihed applying the phos acid treatment like Ospho, you simply re-wet what you have treated already with more product, keep it wet with the product for 10-15 minutes taking care not to let it dry, then rinse with water. If you have crusty areas scrub with a wire brush while you are doing this. Once you rinse it's neutralized and epoxy will adhere. Sanding won't work due to the microscopic pores that metal has, only the way I described or media blasting. You will get some flash rust but provided it's not excessive you can prime over it with no loss of adhesion. Many will buzz the panel with 80 grit after neutralizing to get rid of the flash rust though.
If you use SPI be sure to read the Tech Manual pages on epoxy (included with your order) and follow the instructions to ensure sucess. You can also go to the SPI forum and ask questions there. Myself or others will be happy to help you.
FWIW I have no affiliation with SPI other than being a satisfied customer. And in case anyone is wondering about the quality of SPI products, the 2015 Pebble Beach Concours D' Elegance Best of Show winner used all SPI products. They make a terrific true hi-solids polyurethane clear, as well as many other nice products at a fraction of the cost of the Major paint suppliers and their quality is as good and in many cases far better than any other manufacturers premium paint lines.