media blasting - special considerations?
 

I tried last weekend to start media blasting the coupe body to start tackling the rust to see what shape the panels are in to start the repair.

My little campbell hausfield blaster and I were no match for this task. I'd better find someone to do this for me as I'd be here for months.

There aren't any places I know of in the area (Winchester VA) that are close that would do media blasting for a full car body but there is a local powdercoating shop that I was thinking of calling and asking of they would do it. They powdercoat auto frames and other large items. I am familiar with their work on patio furniture, wheels, and other items and they do a great job.

What special considerations should I take when looking for a shop that would media blast my coupe body? And how would one expect it to be priced?

By the hour or by the job? (know this probably varies between shops)

I would suspect that a company that understands media blasting would be competent enough to not destroy the body and I know it will may come out looking more haggard than when it went in with the rust coming off and the holes appearing. I just need a good working 'canvas' to start the metal work.

The front fenders are fiberglass on my coupe.. I can't afford metal and this is how she came to me so I can handle them on my own.

Re: media blasting - special considerations?
 

Ask a shop what media & pressures they use. To strip the paint, it is best to use plastic at about 35 lbs., and then the fastest way to get the rust to disappear is to use Aluminum Oxide at about 45 lbs. Low heat build-up when AO is used at that pressure. AO is much sharper than glass or sand and thus can be finer in grit to do the same job. DO NOT ASSUME just because they do media blasting that they will be competent in your sheetmetal. Have a talk so both of you understand what is expected.

BTW, in our area it generally runs about $125 an hour and to thoroughly do a Coupe body, doors, deck lid, tank, W/S frame and all of the floor pans (removed) and the body on a rotisserie takes about 6-8 hours.

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Re: media blasting - special considerations?
 

When you think about it money wise its a deal. Ive been sandblasting bits and pieces with my little compressor about 3 years now and I'm still not Done.

Re: media blasting - special considerations?
 

Around Va.Beach there are a number of Soda Blast outfits. Some are mobile,they do alot of paint removel from boat bottoms. There also set up at Hershey in the back of the orange field. Theres another outfit in Richmond,hes allways at Field Day of the Past (sept 17-19) 3 years ago he wanted 800.00 to do a Tudor body (no fenders,hood) in my yard.

Re: media blasting - special considerations?
 

I'd certainly have to take the body someplace and not have any of the work done in my yard. I live in a 'blue blood' neighborhood with ex professional football players, Public Utility VPs, and other 'think-they're-better-than-you' people with 'sticks up their you-know-where' so any blasting won't happen around here. I get all my work done behind closed shop doors. :D

Having the knowledge of an estimated time frame (6-8) hours and a ballpark idea of per hour ($125) tells me my wallet isn't ready for this part of the restore yet. I'll have to wait a while.

Thanks to all for helping with their estimates and suggestions.

Re: media blasting - special considerations?
 

Higher pressures and you run the risk of ruining the sheet metal. Took me 15 -20 hours to sand blast mine, a coupe. I recycled the sand. Would have preferred to have it media blasted, but never had the coin. If the panels get hardened you've ruined them. Bob

Re: media blasting - special considerations?
 

The size of the nozzle is also important. I use a small nozzle 3/32", however it enlarges to about 1/8" before I replace it. A large nozzle risks damaging the sheetmetal.

Re: media blasting - special considerations?
 

Question for Bob - How can you tell if the panels have been hardened or become hardened during sand blasting??? Thanks, Harold

Re: media blasting - special considerations?
 

I wasn't impressed with the media I was using and I was probably using too high a pressure. I was using the 'Black Diamond" grit I got from Tractor Supply. The wrong stuff to use for this I'm finding out.

The blaster I was using was a birthday gift. It's probably barely adequate but I won't tell my darling wife to got it for me.

http://www.amazon.com/Campbell-Hausf...3298108&sr=8-2

I tried it out on the cowl panels that I need to replace to get my feet wet with the process to see how long it would take and the results I would get.

I'd probably have better results with a different media and the right pressures.

I'll have to keep reading and understanding the process and if I get better results with my testing I will probably end up doing it here in the shop if I can get the right technique and results.

I'd want to make a 'bay' inside the shop as well to help hold some of the media and cover up everything else. It will go everywhere but I'll try to contain some of it.

I may regret doing this myself but I'lll give it a shot.

Re: media blasting - special considerations?
 

I'm assuming(asking actually) that sandblasting wheels carries much less risk of 'ruining' the metal(?). Seems like there's not much that could go wrong(other than going slow and wasting material).

Re: media blasting - special considerations?
 

I don't think there is any risk sandblasting rims at almost any pressure. The metal is about 12 ga thick and the spokes are heavy gauge also. I have found that sandblasting 19 ga sheetmetal, which most model A sheetmetal is made of, is not to prone to warping if done by homeowner type equipment. It is the big commercial equipment with high pressure and large nozzles that can really damage sheetmetal. I suppose smaller equipment could warp sheetmetal if the pressure was set very high and the nozzle very large, but most compressors for home usage wont run long with high pressure and a large nozzle.

Re: media blasting - special considerations?
 

I have been warned not to blast one small area down completely before moving on since it may be either buckled, cause waves in the panel. When i did my coupe I would make several passes. Also, I was warned that too much pressure, and time in a small area would make it difficult to later take out small defects(do body work) since the metal would become embrittled. I had a small compressor so I did most of my work after the pressure built up. I also bled off condensation frequently. I used sand. about three passes and it became powder. I followed each session with metal prep/rust converter that I sprayed on, then wiped off with a clean rag. Bob

Re: media blasting - special considerations?
 

Banjoman. Do it outside, or behind a fence. I laid out 6mil plastic, then a tarp. I held it down with 2x4s. This caught the sand for recovery, and reuse. You don't want to fill your garage with the dust, and fine particles. Also get a hood, and a good source of fresh air to breath. The paper mask won't prevent inhaling the fines, although silicosis is a cumulative disease, and eventually if you are a smoker you won't defy the odds. This is a hot, miserable job, and worth every penny you pay to get it done by a professional. Bob

Re: media blasting - special considerations?
 

Harold, I don't know how. The body guy that refused to work on my car after I admitted I had sand blasted it was the reason I became aware that the sheet metal can become hardened by sand blasting. I understand soda blasting is less destructive. Me, I usually don't listen and learn the hard way. Bob

Re: media blasting - special considerations?
 

If I had a fence to go behind I'd do it. I have a hood and use a paint quality respirator. I know of the dangers of the dust and how much of a mess it makes.

I'll wait until air temps are in the 50s or below to tackle this. I have so much to do on this that I can keep going with the other aspects of the car till the temp makes it easier. I'll still see what prices I can get and will still do my rims and other small parts to see what works best.

I'm glad for the input I'm receiving here.

Re: media blasting - special considerations?
 

No matter what blaster you use there are a few things you must have to have for it to work. One is a compressor big enough, say 18-20 cfm (that is 5 hp). Two is dry air, like with an oil seperator & dessicant dryer. Hose big enough, 0.5" or bigger and the shorter the better. The black diamond from Tractor supply is what we use because it is rather fine. We use the nozzle size just smaller than 1/8", about 40 psi. and back off from the panel to just remove paint, slowly. WE also use a fresh air system and ventilation similiar to a paint booth.

Now when you add up all the equipment and media. Without adding any value for you time. It's very economical to pay a qualified business to do the work. The big question is which business is qualified.

Re: media blasting - special considerations?
 

I just use a small craftsman unit for portible sandblasting and black beauty sand, works great. I have been using the same set up for about 6 or 7 years only cost about $45. Sandblasted whole car bodys 5 or 6 harley frames, tools and even the inside of my wood stove pipe lol (never herd of the phrase meda blasting though). Also have a blasting cabinet for small work. Doing my rims right now I get one done in about 15-20 minits tops. (Never sandblast inside or around your undercarage assembled.) when i was 15 I decided to sand blast the frame of my jeep dam near ruined it sand found its way into every joint and bearing in the car found its way even into the engen and down into the oil pan; its Nasty stuff. also that day i learned the lesson about sandblasting indoors it was winter so I decided to sandblast insided. Killed my grage door opener got into all my power tools, angle gringers, skill saws drill press just about everything. 6 years latter I am still findind sandblasting beads places and they are still reaking havic. Just about 2 mounths ago the draws in my craftsman tool box had started letting go. After some quick ivestigation I found that the draw slides were filled with sand blasting sand and from opening and shuting after all this time with sand in there had ruined them. That was the only time I have ever sandblasted inside.

Re: media blasting - special considerations?
 

I am a retired sandblaster.

Here is a vid I made of a cheap blaster.

http://i86.photobucket.com/albums/k1...Movie_0001.jpg

Re: media blasting - special considerations?
 

Thanks for the video. As you have shown; my biggest problem was an even flow of the sand. I had to constantly adjust the pickup tube in the sand.

Re: media blasting - special considerations?
 

The standard metal tube poked into the sand is useless.

I should make a better vid one day.

I was blasting behind my hand to stop the cam lens being peppered, so it obscured the vision.

And i should demonstrate a a bit better that the sand only pools out of bottle to a set "puddle".

When blasting, it only takes what it wants, when blast is stopped, sand stops flowing too.