Painting engine this weekend - please critique this process

[philosopheriam]

Folks,

I plan on painting my empty engine cases this weekend (guts removed). Here is the process I plan to use:

1. Plug bolt holes & all ports
2. Mask important surfaces with duct tape (resists abrasives)
3. Soda blast cases with XL grade soda
4. Unmask cases and rinse with hot water and dawn dishsoap
5. Mask cases with painters tape
6. Prime with VHT engine primer
7. Paint with VHT universal aluminum
8. Let paint dry for 24hrs
9. Bake cases in oven at 200F for 1hr

Thoughts?

Would you folks recommend the use of an aluminum etching product?

 

[Nessism]

Just went through this and didn't mask a whole lot before blasting.

Make sure to clean out any oil passages really well.

 

[philosopheriam]

Just went through this and didn't mask a whole lot before blasting.

Make sure to clean out any oil passages really well.

Ness,

I never mask carbs when I soda blast them, either - I may just put some duct tape on the deck surface and the oil sender mounting area and then blast away. I will clean the cases by rinsing/dunking them in hot water - this should dissolve any soda that's left behind. Lastly, I'll blow them out with compressed air.

I was thinking of using a 50/50 water/vinegar mix to do a final rinse on the exterior of the cases as a poor mans etching solution. Primer after that.

 

[sharpy]

I didnt use any primer and originally only the top case on a GS 1000 is painted. Can put in oven soon as painted as it will come out better i think. Done it lots of times and seems to make the paint blend in when still 'wet'

 

[rustybronco]

Phosphoric acid will etch aluminum. You can get it as prep and etch at your local home improvement store. It will darken the case so don't leave it on too long. Ten minutes is probably enough.

Be sure and degrease the cases well or you'll end up with the paint not wanting to adhere to the metal properly. You can see what I'm talking about in this post.

http://www.thegsresources.com/_foru...t-bought-another-junker&p=2119913#post2119913 picture #4

I hear Palmolive dish soap and water makes an excellent degreaser as does simple green and water which is what I used on mine.

 

[sharpy]

oH HAVE YOU REMOVED THE BARREL STUDS SO IT FITS IN THE OVEN OR YOU LUCKY ENOUGH TO HAVE A BIG ENOUGH OVEN TO USE. opps shouted sorry

 

[philosopheriam]

Phosphoric acid will etch aluminum. You can get it as prep and etch at your local home improvement store. It will darken the case so don't leave it on too long. Ten minutes is probably enough.

Be sure and degrease the cases well or you'll end up with the paint not wanting to adhere to the metal properly. You can see what I'm talking about in this post.

http://www.thegsresources.com/_foru...t-bought-another-junker&p=2119913#post2119913 picture #4

I hear Palmolive dish soap and water makes an excellent degreaser as does simple green and water which is what I used on mine.

Easy-off oven cleaner works quite well as an initial degreaser.

For a final wash, regular boring Dawn dishsoap works quite well - it's the same stuff that they use to clean animals when they have been in an oil spill.

Before I disassembled my engine, I took it to work and blasted it with a hot-water pressure washer. So, it's pretty darn clean

After I soda blast it, I figured I'd fill up my bathtub with hot water and Dawn and dunk the cases repeatedly - my thinking is that any soda stuck in tiny crevices will be dissolved/dislodged. Then, I'll just rinse everything off with clean hot water and blow it off with compressed air.

 

[chuck hahn]

I use acetone as the final wipe down before paint. That way theres absolutely no residue from anything left behind to spoil a spot or two.

Second...when you blast the head and jugs, plug the oil passages and the valve bucket wells. Dont need them full of loosened crap or residual blast media that you cant flush out. The case halves arent a big deal as youre gonna be spreading case sealer around the halves anyway.

I always give the U shaped areas the crank and tranny seals sit in a little wipe of sealant also as a back up. never have had any leak.

A car wash or power washer is more effective at blowing water thru the passages than simply dunking parts in and out of the tub.

 

[philosopheriam]

I own a pressure washer - it's just starting to get a bit chilly out here!!!

 

[Joe Garfield]

I have experience with auto paints but not paining an engine so I don't know if this will all apply:

If you want to mask any straight lines, the 3M 'straight line' tape from auto paint stores is worth the cost. It is the stuff with a 'masking tape' texture, not the vinyl tape which is for curves. There are different widths - the 1/4" seems to be the most versatile, and the 1/8" is good for small spaces or broad sweeping curves. Regular painters tape lets paint bleed under it.

Also, I use PPG 'Acryli-clean' (DX330) as a final step before priming or painting. I guess it is technically a wax and grease remover, but it is really good stuff. You wet/wipe the surface and any remaining grease/residue will rise to the surface of the liquid film. Then wipe it away with a clean, dry cloth. I find it to be the best thing for preventing fish eyes. It is good stuff to have around the house as it removes adhesive residue from most things (great for removing stickers, etc) and it's not terribly expensive. It is safe on metal, painted surfaces, many plastics and fiberglass, etc.

 

[Scratcher09]

I use simple green and scrub with various wire brushes and a pressure washer does a great job. Then before priming I wipe down with degreasing solvent (acetone or lacquer thinner work). Never underestimate the value of meticulous prep work--it will make or break a paint job.

 

[philosopheriam]

I posted pictures of the cases/cylinders/valve cover after blasting and rinsing on my project build thread:

http://www.thegsresources.com/_foru...ion-Performance-Rebuild&p=2125548#post2125548