Definitive Answer on Media Blasting, Please...

[timbn2]

i've heard many conflicting things regarding healeys: sandblasting damges panels, soda blasting is the best... etc.

what is everyones experience? sand? plastic? soda? others?
thanx

 

[Skip & Lynne]

I have used fine blasting sand with good results but be sure to use FINE sand. It has a powder like consistancy with NO little rocks. Don`t get the stuff from the bulding suppliers like playground sand. Find a good sand plant and get good dry sand. I have a 15 hp 2 stage compresser and it keeps up fine at about 100 lbs pressure on a 100 lb pressure pot. I blasted all the steel parts doors, fenders, frame etc. As for the Aluminum shrouds I had them chemically stripped. I didn`t have any warping or scratching of any panels and after I blasted them I sanded everything with 220 paper and epoxy primed.

 

[JamesWilson]

As Skip & Lynne have done I stripped the shrouds using chemicals- these worked well.

I had the chassis and inner body, steel wings and bonnet blasted by someone with experience and did not do that myself. They used a fine aluminim oxide grit and a low-ish pressure. Everything cleaned up well without any warping or waves. Its a very messy job and leaves grit everywhere that can be a bad contaminant for any later painting or mechanical work. The panels need to be cleaned thoroughly afterwards- not a problem with wings but the innerbody is trickier.

I used a cabinet with a siphon feed gun, a compressor rated at 28CFM and a medium aluminium oxide grit for blasting suspension components and other odd bits myself. This worked well and cleaned the parts more effectively and quickly than other methods. I didn't worry with these about distortion.

NOTE too it is strongly recommended that you not use sand itself, and other non-silca based media are less dangerous. Silicosis has been found associated with using sand and professionals do not use it. Whether you'd want to use it for a small job is your own call but commerical suppliers of the blasting material don't usually provided it- they know the dangers (and their potential liabilities, I suppose).

Have the blaster prime the panels immediately for the bare metal will soon start rusting. The blasted panels provide a good foundation for paint- better than the unblasted surface for paint adhesion.

Here's a fairly good overview of the issues in blasting:

https://www.team.net/www/morgan/tech/blasting/mediablast.html

 

[BlueRidge1]

I'VE BEEN HAVING GOOD RESULTS WITH THE OLIVINE ON BODY PANELS. I USE FINE BLASTING SAND ON CHASSIS PARTS AND FINE GLASS BEAD ON STUFF LIKE CARBURETORS. SOME STUFF LIKE THE REAREND HOUSING AND DISC WHEELS AND BRAKE DRUMS I HAD SHOT BLASTED WITH LEAD (THEY DO THIS AT PLACES THAT MANUFACTURE WROUGHT IRON FURNITURE.)THAT WORKED REALLY WELL AS I PUT THE ENTIRE REAR END IN THE MACHINE TURNED IT ON AND ABOUT 45 SECONDS LATER IT LOOKED LIKE NEW.OF COURSE I COMPLETELY DISSASEMBLED IT AND CLEANED IT BUT DID'T REALLY SEE ANY ILL EFFECT FROM IT. BOB

 

[Bruce Bowker]

You want to make sure you do not over pressure the blasting. It isn't necessarily the media that causes damage but how close, how long in one area and how much pressure.

Bruce

 

[aeronca65t]

Very good discussion of this subject ~HERE~

 

[timbn2]

so can any place that does sand blasting also do other medias, or is the equipment used completely different than the sand blaster?

 

[John_Progess]

My frame is being sandblasted for rust removal by a guy that does media blasting in our area. I will have him blast the sheetmetal fenders,doors,hood and trunk with plastic media which is designed to remove paint only, no rust. The aluminum I will chemically strip. I have done this on my other cars with good results. Have a good day!

John

 

[John Loftus]

I had my chassis and body panels plastic media blasted by a shop that claimed they would not warp the panels. (The shrouds were stripped mainly with an torch set to a long low flame to bubble the paint and scrap with a putty knife and some chemical stripper to get to hard to reach areas.) Everything looked great until I started mounting the panels and found at least three that needed to be reworked by the panel beater. I'm sure the commercial guys generally work with higher pressures and more flow than a DIY setup .. time is money and all that. So if you get an operator that is in a hurry or inexperienced with thin gage.. there goes the panel.

I have heard great things about soda blasting including being able to use it on aluminum and would check out those sources next time around.

Good luck!
John

 

[Skip & Lynne]

The nice thing about the way I did mine was that I used the fine sand at a high pressure and didn`t have to stay in one area over a few seconds.Usually one quick pass got the paint and primer sometimes 2 passes if there was any rust. It is the friction and mechanical action of the media that warps things.

 

[Bruce Bowker]

[ QUOTE ]
so can any place that does sand blasting also do other medias, or is the equipment used completely different than the sand blaster?

[/ QUOTE ]

If they sand blast small items I would certainly think they have a selection of media, as opposed to a company that blasts bridges.

Bruce