Not the Blast You Might Think I've had a lot of distractions keeping me from working on the car, but I've also been spending a lot of time media blasting. The subject of DIY chassis blasting pops up now and again, so I thought it might be worth sharing my experience so far.
First, let's be honest. You have to be a masochist to take this task on unless you have access to some premo equipment. If there is one part of this project that I would have liked to farm out, this is it. But I'm a pathologically CSOB trying to do this on a budget without putting more actual cash into the project than the car will be worth coming out.
Second, the best time to blast a chassis is at the beginning of the project, not 1/3 to 1/2 of the way through like I'm doing. Having the car stripped to bare metal from the start would just make the rust repair more pleasant, and save time stripping areas piecemeal to find the sound metal. I didn't take my own advice simply because I had serious doubts about prospects for success going into the project. DIY media blasting is a huge investment in time, and not a small investment in $$. I wanted to make sure I could actually make this car straight and sound before making that investment. Also, with all the sheet metal that was replaced, there is a lot less left to blast now than in the beginning. Enough of coulda shoulda, here's what I'm doing.
I'm using the el cheap HF 40 lb. media blaster
I've never used a blaster before so don't have a comparison, but it seems to work okay. I'm running it with about 50 psi pressure which is about 40 psi delivered when in operation. The unit has 4 ball valves to control air to the tank, air to the nozzle, media to the nozzle, and a shutoff at the nozzle. Every review says the valve at the nozzle will wear out within a few minutes of use. Mine lasted a surprisingly long time, but it has gone now. I believe Cary recommended buying the optional deadman valve which I think I will do next time I'm in town.
The thing is a bit fiddly to dial in, but once you do, it operates pretty well. The ceramic nozzles are a little prone to clogging when new because they start with a small opening which widens with use until it has to be discarded. I've read complaints that the nozzles wear out fast, but I blasted at least 50 pots of media before my first one wore out. The area that can be blasted is small - only about a square inch with a new nozzle, a little wider as the nozzle wears, but once you have grit flowing, I build a steady rhythm and can strip about 2 sq. ft. before my 60 gal. compressor cycles on. By that time, the hood is starting to fog so it's a good time for a short break.
The biggest frustration is the hood. The blaster comes with a worthless POS so I bought HF's "upgrade" hood. Also a POS that flops around on your head and fogs up as soon as you put it on. I wound up getting this hood:
https://www.amazon.com/gp/product/B00442XOK...=UTF8&psc=1I'll describe this one as adequate, but barely. It has better ventilation so doesn't fog too bad as long as the temperature is not too hot or too cold and the humidity is not too high. Because of this, I'm limited to blasting in the mornings and evenings. The hood also has a piece of aluminum window screen in front of the plexiglass window which reduces the amount of peppering and etching the plexi gets. I'm still on the original piece but frequently remove it for cleaning and polishing. I think I'm going to try a glass window to see if it lasts longer (with safety glasses worn under the hood of course). Had I seen this hood when I started, I probably would have given it a try:
https://www.fullsource.com/north-safety-pa1...ASABEgLRsvD_BwE What I have is working and an hour or two in the morning and the same in the evening is really about as much blasting fun as one needs.
For media, I'm mostly using medium crushed glass at $21/bag at my local lumber yard. The last time I passed through Billings, I picked up several bags of
Black Diamond Medium Blasting Abrasives at $8/bag. It works almost as well as the crushed glass but seems to wear out faster. Unfortunately, it is a 300+ mile round trip to get it which eats up the savings. I have my tent set up with a tarp on the ground to catch spent media. I vacuum up the used media with the shop vac and pour it through a window screen into a bucket for reuse. The cheap media seems to be good for 2-3 trips through the blaster before it become too dusty to use (oh yeah, I wear a P95 dust mask while blasting). The crushed glass is good for at least 3 and maybe 4 cycles through the blaster. It's a pain in the ass, but saves money.
So far I've spent probably 12 hours actually blasting and another 4 or so vacuuming and sieving media. I've almost completed blasting the front clip of the car which I think will be the most difficult. That does not count the outer body skins which are being stripped with a
stripping wheel but I may switch to chemical stripping. My guess is that the front clip is about 1/3 to 1/2 of the total job. So making progress slowly. Like I said, you have to be a masochist.
Now for a few pics:
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Warning: these pictures contain nudity. Parental discretion is advised.]
Sorry for the wonky colors. The tent throws an odd light that doesn't always adjust out.
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