Looking to get my 12 bolt blasted when i do the rest of the frame and components. what is the best way to do it? what is going to protect it from getting sand inside? should i pull the axles out and seal up the ends of the housing? should i leave the drums on, since they're getting trashed anyway? what about the yoke? ive heard of people taping stuff up, but i think that only protects it when the blaster stays away (no direct contact).

whos had it done, and what were the results? ive thought about taking a wire wheel to it since i did do it about 5 years ago when i used krylon, but this is going to be bc/cc so i want it really clean.

thanks, tim

I've blasted a couple of them, I've been trying to search out how I did it, maybe somebody can find it.

I don't want to miss anything, and its been a couple of years, I think when I did it.

Rob

Heres a jig I made up for it.

http://www.1969supersport.com/ojig27.jpg I use this with the cherry picker to hold up the complete 12 bolt axle. Just to paint the end of the axle that sticks out from the backing plate, that you can hardly see when the brakes are installed. This is really anal, like most of the stuff I do...but I have to have it right.

Rob

Its on this thread, I'm 1969ss.

http://www.camaros.net/forums/showthread.php?t=92899&highlight=sand+blast+rear+end

Rob

I had mine completely gutted, then taped up all the openings and then had it blasted. I then had it painted at a body shop, and reassembly was done afterwards ( with all new seals and bearings ). Your bodyman will thank you, as they are much lighter this way. You can check my signature for pics.

Had my wagon original 10 bolt blasted by a local shop...left it completely assembled (minus control arm bushings and brake components) and had it able to roll around on two wheels/tires bolted only to axle hubs. All I did was seal off the vent and pinion seal with duct tape. Then did a visual internal inspection & lube change but before prime/paint. After paint, just replaced the brakes, stainless lines, and suspension bushings.
All was good to go. :thumbsup:
On the '70s 12 bolt, different story...total disassembly, weld tubes and bearing cup mod, then powdercoated.

You can't keep the sand out. I stripped mine down, plugged every hole I could find and it was still full of sand after I got done blasting it. I ended up washing it out with soap and water and flushing it out with the garden hose. If you have it blasted fully assembled, sand will get inside and it will shorten the life of your bearings, seals and gears.

Tom

You can't keep the sand out. I stripped mine down, plugged every hole I could find and it was still full of sand after I got done blasting it. I ended up washing it out with soap and water and flushing it out with the garden hose. If you have it blasted fully assembled, sand will get inside and it will shorten the life of your bearings, seals and gears.

Tom

Must be something you don't understand about taping them off.

Rob

Must be something you don't understand about taping them off.

:yes: Kinda what I was thinking...
I found no residue under the duct tape and I know the guy doing the blasting was careful around those areas.
I believe the blasting media he used was "Star Blast" or something like that...it's a dark gray/black color.

Find someone that will use Walnut Shells, or some other blasting media that won't hurt the bearings IF some gets in...

Must be something you don't understand about taping them off.

Rob

Rob,

No tape I know of is gonna withstand sand driven by 100+ psi of air pressure. All it takes is one lifted edge and you've got a real mess. If you choose to take the risk I guess it's your rear end at stake. ;)

Tom

thanks for the replies... whats the difference with the walnut shells? will they break down and not cause a problem with the bearings? thanks, tim

thanks for the replies... whats the difference with the walnut shells? will they break down and not cause a problem with the bearings? thanks, tim

I wouldn't want walnut shell dust or sand blast sand or dust, or any other thing in a rear end.

Rob

Rob,

No tape I know of is gonna withstand sand driven by 100+ psi of air pressure. All it takes is one lifted edge and you've got a real mess. If you choose to take the risk I guess it's your rear end at stake. ;)

Tom

A couple of us posted on here that we sandblasted and they came out clean, then you come out and say it can't be done.

I will agree with you on the part that it might not work for you or other people, it depends on who is doing the blasting, and who is doing the taping.

I do a lot of sand and bead blasting, with siphon and pressurized units, and these twelve bolts can be blasted with a pressureized blaster with out getting any sand in them.

On my website I have gone over pressures at the compressor and at the blaster, as well as actual pressure coming out of the blaster.

If you do a decent job taping the yoke and axle ends with duct tape, it won't leak.

Put two or three layers of duct on a piece of metal, then blast it directly, I'm not saying to just hold it on there, but it will take more then you will ever give it blasting that axle.

Rob

A couple of us posted on here that we sandblasted and they came out clean, then you come out and say it can't be done.

I will agree with you on the part that it might not work for you or other people, it depends on who is doing the blasting, and who is doing the taping.

I do a lot of sand and bead blasting, with siphon and pressurized units, and these twelve bolts can be blasted with a pressureized blaster with out getting any sand in them.

On my website I have gone over pressures at the compressor and at the blaster, as well as actual pressure coming out of the blaster.

If you do a decent job taping the yoke and axle ends with duct tape, it won't leak.

Put two or three layers of duct on a piece of metal, then blast it directly, I'm not saying to just hold it on there, but it will take more then you will ever give it blasting that axle.

Rob

I guess we both have our opinions.

I have sand blasted rear ends in the past without disassembling them and it always made me nervous. This time I decided to strip it and was glad I did because it got sand in it. Maybe I just don't understand taping as you implied. Perhaps you could include it on your website so I can learn how to do it correctly.

Tom

Until I do another one, this might help. I keep lacquer thinner in little metal spray cans, heres how it works.

Rear axles are a little rough on the edges, kind of like cast iron. So there hard to clean.

Getting the metal clean is the secret to having the tape stick, so, when I clean cast iron I will spray an area, then take an air gun and literally blow the lacquer thinner off, in kind of like sheets.

If its pretty greasy I will use a fine wire brush with lacquer thinner, then after that spray it a time or two again with just thinner and an air hose to blow it off.

This also works for painting, but you should follow up another spray treatment with acryliclean.

I believe I said something about maybe up to three layers of duct tape from the thread I posted on the camaro forum.

Once you get it this clean, the duct tape will really hang in there.

Then when you blast it, don't get to aggresive and hold the blaster at any area where the tape is not tight. In other words, any open area behind the tape that is not against a definite surface.

In all actuality, its pretty easy to do and keep sand from getting in there.

But, when I do another one, I will get clear close up pictures of the cleaning and taping, and also how to blast it.

Rob

Rob,

No tape I know of is gonna withstand sand driven by 100+ psi of air pressure. All it takes is one lifted edge and you've got a real mess. If you choose to take the risk I guess it's your rear end at stake. ;)

Tom

Ya Rob.. what u thinking hheehe

I got a little sand in mine with taping, but I washed it out about 5 times and then blew it out. I think it should be fine though.

I just found this on my web site about cleaning cast iron, its in this section.

http://www.1969supersport.com/paintprep.html

Rob

i guess im still kind of at a loss as to what to do. knowing what i know now, i dont think i would have a problem with sand. id use a whole roll of duct tape, if thats what it took. my other option is to tear the rear end apart, but it was only rebuilt about 5000 miles ago.

which seals would have to be replaced? if it was a matter of tearing it apart, putting it back together and having a shop only reset the backlash i would do it. but if i have to pay for new axle seals, pinion seal, etc it would get expensive fast.

I can't remember how I taped it:clonk:maybe its old age, but I do remember it wasn't hard to do.

I'll be 66 in 5 days, I'm probably in the first stages of alzheimers.:)

Rob

i was thinking of removing the axles shoving some old shirts into the tube and then bolting a piece of 1/8" sheet metal to the tube ends using the flange. id then tape it off really well. i just dont know what to do about the pinion.

again, since im kinda now leaning towards being safe, could i reuse the axle seals and pinion seal, or are they going to leak?

If it was rebuilt 5000 miles ago, leave it alone. Just tape it up and blast it.

I wouldn't take the yoke area apart for sure unless there was a problem with it.

Here's mine, done with soda. I was changing the gearing at the time, so it was really easy.

http://www.chevelles.com/showroom/data/500/medium/rear_end_005.jpg
http://www.chevelles.com/showroom/data/500/medium/rear_end_003.jpg

Well Dave P., that solves it :thumbsup:

Also a very good article on how to rebuild your 12 bolt and mask for sandblasting in Chevy Punch #3 written by biggearhead. That is the, on line, downloadable magazine available by clicking on the link at the top of this page (free). It gave my the courage to rebuild my own 12 bolt, I'll let you know how it turns out. The new gears haven't arrived yet.

I had some old eraser wheels that fit perfectly in the axle and pinion holes and left the cover in place with the gasket. Had no sand inside the housing.
http://i134.photobucket.com/albums/q81/71ls1chevelle/MVC-538F.jpg
http://i134.photobucket.com/albums/q81/71ls1chevelle/MVC-540F.jpg

I had mine completely gutted, then taped up all the openings and then had it blasted. I then had it painted at a body shop, and reassembly was done afterwards ( with all new seals and bearings ). Your bodyman will thank you, as they are much lighter this way. You can check my signature for pics.

I did mine the same, except I had mine powder coated.(gloss black) $125.00 for the powder coating and $30.00 to blast it. Its a little dusty now :D


http://i142.photobucket.com/albums/r119/TT402LS1/S5000093.jpg

Ron

[quote=floyd66;1508795]Well Dave P., that solves it :thumbsup:quote]

Thank You, all those years in the ShipYard finally paid off.:D

I should add that I used some rtv under the wood caps, and Spraycan lids, and duct tape seal the ends very nicely.:thumbsup:

I should add, that if You're gonna re-build your Diff, I got all the goods to do it now. And, I'm just Down the road, and there is an excellent place to blast it in Bellingham. He's very reasonable, and will fit You in.