Blasting, Paint, and Aluminum

[mjperk]

Hello there! First time poster on this forum. I came here after finding some beautiful engines that members had repainted and am about to start my own. I did a search but came up with few results so I'm hoping you guys can help me out.

I just got my engine back from the shop and it has been completely blasted--it is 99% clean. I plan to use the VHT engine primers and paints to do the job. I was unable to source the VHT prep spray, so I'm going to use Eastwood PRE instead. I know it may be expensive overkill, but I figure that if I'm going to go to this much trouble and expense that it is relatively cheap insurance.

My question is in regards to spraying over a blasted surface. I see that a lot of guys who redo aluminum boat hulls sand down to shiny metal and use an etching primer. I do not believe the VHT primer is etching, nor do I see how it would be possible to sand down to shiny metal in all of the nooks and crannies on the engine. So in short, do I need to do any prep work to my sandblasted parts other than a thorough cleaning and degreasing? It may be of importance to not that by the time I get to painting, about 6 weeks will have gone by since the blasting so it won't be fresh by any means.

Thanks!

 

[bgtuth]

Hello,

I painted my engine no long ago with VHT engine enamel after being blasted and left a while, I would give it a really good scuff up with steel wool pads/sandpaper as mine chipped in a few places even after spending ages make sure the surface was degreased and free of any contaminates. I think getting rid of any sign of oxidation will improve the bonding hugely, I followed the VHT instructions exactly and used their VHT engine primer. Just remember the paint is a little fragile until it is baked on.

Good luck!

 

[o1marc]

The blasted surface is ideal for painting the engine. Nothing you do to the blasted surface can improve it's ability to have paint or powder adhere to it. Clean it and shoot your paint.

 

[Tim]

leave it bare aluminum and save yourself time trouble and money

 

[AlphaDogChoppers]

While Tim's suggestion has much merit, and I have done that with budget jobs, Marc is right on the money when he said that you already have the ideal surface for painting. Just make sure it's clean. I like to put acetone in a trigger spray bottle, and use that to clean things. Acetone is low in toxicity, while being a very effective degreaser. Acetone in a spray bottle is a lot less expensive than buying more toxic spray carburetor or brake cleaners.