sand blast and paint motor?

hi guys. i have a 550 maxim motor i would like to paint. i guess i should sand blast it first? and if i do, what precautions do i need to make before doing so? also, i have seen a motor on here somewhere that was painted. it was one color, and then had the "ribs" of the motor painted a different color. how is this done? and is there some pics out there? thanks.

 

i found the pictures, but still not too sure on sandblasting, and what kind of paint to use because of the heat.

 

The Cam Cover can be Stripped without Blasting.
The Cover looks great Polished and the raised Fins and Logo painted.

The Engine can be Blasted; but sand might be too harsh a Media.

Google: Media Blasting and determine which Media you want to use to Prep the Block for painting.

 

Normally on the dirt bikes I restore, I paint the cylinder and head flat black, then take a dremel tool with a sanding wheel (or small sanding block) on it to sand the paint off the edge of the fins. I am guessing this that the engine you saw was done similar to that, then maybe a small paint brush, or pin strip roller to change the color of the edges.

 

hey guys, as far as cooling goes i read a few times that black helps air cooled engines cool better, but have any of you ever noticed a diference meaning if the engine was running hotter or colder or had a failure due to the paint becuse it was running hotter

 

There is an earlier post on this. If not mistaken, it came down to not enough difference either way to matter. If wrong, I apologize...

skillet

 

here's a painted motor

 

That looks REALLY nice...

skillet

 

is it ok if i blast it too? or will it ruin it?

 

also, i can adjust my pressure and use play sang right

 

thank you, looks good

 

you can blast the valve cover just don't hit the gasket surface and if you ever want to shine up the YICS and stripes, mask them
play sands not the best but it'll do, it's pretty rough, i use about 40 psi with sand
then scrub it till your sure it's clean then do it again

 

I'm going to try a Soda Blast ... real nice results, and the soda is water soluble. A little more expensive, but the I think the results are worth it!

 

There's no reason to Blast the Cover.
The Cover is Bright Alloy and is UNscratched below any paint on it. Paint Stripper sprayed on the Cover will remove the paint and leave no blemishes that need to be addressed before repainting.

I think you find that Sand is far too abrasive for Blasting Aluminum.
Why would you use sand when there are so man other choices available that will both Strip and refinish without the course look of the Engine having been Sand Blasted.

 

well i blast it because thats what the INSTRUCTIONS say to do

so will sand blasting

a: thats what i had
b: i like it

 

ok, well if play sand is not the best for aluminum, whats a cheap alternative? money is a issue. just had a baby boy threee monthes ago.

and when you say "the cover", you mean the very top of the motor, that is held down with the allen screws? not too good with the termonology of these motors yet. thanks guys for all the advice, keep it comming.

 

I agree, the local blaster dude advised me not to sand blast aluminum. I read another chap in here that used soda with pictures and it turned out nice, and didn't harm the metal. If you have a local blaster pro, ask him what other options there are.

 

I just finished a rebuild, and used an aluminum polish, and a small rotarary tool for the head, pistons, and all mating surfaces. Labor intensive, but cheap!

 

great guys, ill do some research on the soda. what is it baking soda? hmmmm, well this might help, look at all the layers of paint on this thing. keep me updated on advice. would like to try and get it cleaned here soon.

 

We alway used silica sand to remove rust from auto bodies. That is uasually the media for sand blasting. It resists clumping when damp unlike play sand. It is however "sharp" and too aggressive for aluminum. Although not a concern on thicker castings, it generates heat that can distort sheet metal if not done carefully. I have to agree that soda blasting is a better choice for the softer metals. Much less aggressive and easier to clean up. If residue from the blasting is left it can ruin a paint job.

 

You can buy walnut shells for blasting. I saw them use it on TV to strip a car. It takes off the paint without damaging anything else. They didn't even take out the glass or protect it in way. The walnut shells didn't even scratch it. I am sure it would work great on alloys.

 

If you blast it with Walnet Shell ... you'll probably wind-up with a result you won't want to paint.

The Walnet Shell Media will put a luster on Cast Aluminum that makes it look close to billet.
It can be very pretty.

 

Here's my results with soda blasting and high temp paint...
before..





And after ...







Just make sure you thoroughly clean all the soda residue off before painting

 

One more thing.Aluminum begins oxydizing immediately after blasting. The paints will last the longest if they are for use on raw AL and applied asap after the blasting. You can use an AL primmer such as zinc chromate (needs to dry a lonnng time to harden). Then Other paints can go on it. Check out Eastwood's Aluma Blast. I used it on my Norton but To me it is a bit dull. There are some others but I don't know about them. If you can find it cheap plastic media is what is used on airplane parts (AL).

 

Hey I just blasted my xj750 with Glass bead, which is more expensive then sand but no downfalls or pits, look like a newer engine. now time to replace gaskets.

 

What did you use to block the carb intakes, clutch plates, etc ... very nice job, i've been thinking of doing this for awhile but don't want to get stuff in my motor.

Z

 

For the intakes and everything else I just covered them with 2" wide masking tape. for the exhaust ports I cut small round pieces of cardboard and ind of press-fit them in to act as a port plug.


For painting...
To separate the top from the bottom half I took two pieces of cardboard. On one I cut the profile of the jugs on the back half of the motor to the centerline of the jugs, and cut a profile of the front half on another piece. Slid the pieces in from front and back until the "split-line" between the card board mated up then taped them together..sorry..didn't get a pic of that..

 

Real nice job!

Old socks come in handy don't they.

 

This is amazing!good work

 

Play sand is not desirable because of the different sizes of the granules. Imagine the velocity at which this stuff is hurtling at your soft metals - one big "rock" can do a lot of damage. It's worth it to spend the $$$ for proper blasting media to get consistent results.

 

You can degrease and paint in a well ventilated area !!! Use POR20 high Heat aluminum www.por15.com.