Sandblasting advice sought

[Cobia]

I decided to take to take the engine out of the frame of the J I'm restoring. I'm thinking it'll make the rust removal and painting much easier and faster.
So, does anyone have experience with sandblasting the engine for this purpose and what media would you recommend, sand, glass beads, nut shells, etc. I figure I can remove that pesky aluminium oxidation we all have to deal with and prep it for paint, maybe even paint it in one day. The frame and other parts would probably go just as fast also. Two days and re-assembly begins!!
In the past I've used a soft wire brush on a drill and dremel tool, but it's very time consuming and maybe harsher than it needs to be.
I realize that the media I will need to use for the aluminium will have to be softer than that used on the steel frame and parts.
Your educamated opinions are very welcome.

[crazy steve]

If you're planning on doing the motor without disassembling it, I'd use plastic beads or walnut shells. This will slow the process considerably if the aluminum is heavily oxidized, but if any of the blast media manages to sneak past a seal or gasket it will be far less harmful. The media can get into the darnest places, even with masking; DAMHIK...

For fully disassembled parts or any steel items, glass beads, aluminum oxide, or sand will be fastest.

[motoman]

Soda blasting it all may be another option. Use mine alot for small things. Even used it to remove most of carbon inside at top of #3 head pipe prior to welding where inner pipe had broke loose bout an inch and a half down in the pipe.., plus took bout ten seconds to make the cast flange mount look like new again. Handy item and baking soda is cheap.

[Ken Talbot]

I've blasted aluminum parts with regular media and with glass beads. The regular aggressive stuff cleans quicker, but it does leave a lot of fine pitting. he glass beads leave more of a satin finish. Might be a good idea to try a bit of each on a sample part before you go too far.

[crazy steve]

I've blasted aluminum parts with regular media and with glass beads. The regular aggressive stuff cleans quicker, but it does leave a lot of fine pitting. he glass beads leave more of a satin finish. Might be a good idea to try a bit of each on a sample part before you go too far.

I'll agree that if you're leaving the metal 'au natural' or just clear coating, glass beads should be your choice. But if you're planning on powdercoating, the rougher surface left by aluminum oxide or sand will guarantee a chip-proof surface.

Paint, it's a bit of a wash; depends of what you want the final surface to look like...

[petejw]

hi ken,
they came up well,
what did u end up doing with them,
paint/polish?

[Cobia]

Thanks for the input guys,

Ken, those parts came out looking awesome. What media did you use? Thanks for taking the time to post the pics.

Pete, Motoman, and Steve, Good advice. I just have to locate someof that media.

I plan on blasting the engine assembled. I've covered the intake and exhaust ports with gaffers tape (kind of like duct tape) but will probably make something out of plastic to make them stronger.
I do plan to paint the engine and the frame, possibly most of the other parts as well. Engine and frame black although the frame will be glossy and the engine kind of satin. Will probably clearcoat the peg perches and the fork lowers. We'll see how it goes, i'll keep posting pictures of the process.
Thanks again.

[Cobia]

And the beat goes on....

Well, I got he engine ready to be un-mated from the frame and the frame ready for sandblasting by removing the wiring harness. I will be laying down the assembly on the right side on blankets, remove the bottom engine mount bolts, and lift the frame off the engine. Of course, I'll right the engine immediately after that process.
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Having some heavy lifting equipment to assist really makes it a lot easier.
I had forgotten to drain the oil before starting this process, and knowing that I had to lay the engine on its side to remove the frame, I got the hoist to perform that task. Having a 2 ton hoist at your disposal sure makes it easy to manage the extra weight handling.
Tomorrow the unmating will take place and depending on weather conditions, sandblasting will begin.
We're having a cold front come through and painting below 50 degrees F is not recommended......BRRRRR!!

[Ken Talbot]

what did u end up doing with them,
paint/polish?

Satin black powdercoat:

[Ken Talbot]

What media did you use?

It has been a few years, so I have forgotten exactly what brand/grit it was, but it was a fairly coarse "black sand" type material.

[Cobia]

Wow Ken, even the rotors!!?? Nice finish I bet.
Eric, thanks for the info. I still need to identify a source for the media around here.

[crazy steve]

I still need to identify a source for the media around here.

Try industrial paint suppliers if you can't find someone who specifically sells blasting media. Be prepared for sticker shock....

I'll add that wherever you're doing this, it will make a mess!

[Ken Talbot]

even the rotors!!??.

A bit hard to see in the photo, but the friction surfaces are masked with a special polyester masking tape that will take the heat of the powdercoat oven. You can just see on the third rotor where the masking tape has been removed from the center section where the rotor bolts to the wheel.

[petejw]

wow ken they came up a beauty,
did you do all that urself or have it done professionally?
can you post a pic of the the finished bike?


cobia,
lucky bugger having that equipment at hand,
sure makes life a lot easier i bet.

[Cobia]

I see that Ken.
I'm with Pete... can we see pics of the finished bike. I bet it's a beauty!!
Is it an MNS? Bet it is now!!