sand blasting questions

idiocrates · Post by **idiocrates** » Thu May 07, 2009 8:47 pm

After trying unsuccessfully to find someplace to sand blast my frame it looks like I'm going to be doing this little task myself......so here goes with the questions.

1. What's the difference between syphoning systems and pressurized systems.....and which is the best for this kind of work?
2. Is a "20 gal" pressurized system big enough.......or does one spend all their time filling the bottle with abrasives?
3. For the frame and axle housings what grit is typically used to remove paint and rust?
4. How much abrasive material is typically used on the frame?
5. What kind of abrasive material (sand, glass, slag, soda. etc) has produced the best results?
6. Are the portable diesel powered air compressors what one uses to provide the air......and does it have to be equipped with an air/water seperator system or any other special equipment?

That'll do for now.......but any other advice, tips, and /or tricks would be greatly appreciated. Thanks.

Jim

Jeeps4Brains · Post by **Jeeps4Brains** » Thu May 07, 2009 9:23 pm

I use a 40 lb pressurized system and I have to stop after about 5 minutes of blasting to fill it up again. So a 20 lb one would be sooner.

I have bought bags of blasting sand, play sand and utility sand at the local lumber supply place. Blasting sand worked best but cost more. Play sand has too much moisture. The utility sand has to be strained through a screen wire to remove small stones that will clog the blaster. Lately I have been using the utility sand.

I am trying to remember but I think it took around 20 bags to do my whole frame. That was over a couple of weekends and a few times during week nights. The biggest pain is the filtering of the cheapo sand.

My air compressor can barely keep up, so it gets a break when I stop to fill up the blaster and or sift the sand.

I looked into renting a portable compressor and blaster. The price for that started at $500 without media. It would have been cheaper to hire someone to do the blasting.

If you do it yourself you must wear a respirator, if you don’t you will fill your lungs with the fine particles of silica, very bad.

pfarber · Post by **pfarber** » Fri May 08, 2009 9:28 am

A pressurized pot will give much better performance than a siphon setup.

The good tings about a siphon set up is that you can use plastic sheet to collect the media and keep on shooting. They generally don't clog, but have poor performance due to low CFM compressors most people hook them up to.

Pressurized pots give much better performance, but are a pain to stop and load back up, plus you need to refilter the media as it will not pass large rust or paint chips like a siphon gun can.

The biggest single factor is your compressor. Unless you have at least a 220V 20A motor, and a 2 stage pump, things will take forever. Basically any compressor with wheels or 110V will take forever.

I am on the fence about silicosis and the use of play sand for blasting. Unless you put your puss right up in there for days on end you *probably* have little risk. But then again you could get the cancer after a few days... I would not use sand without a forced air repritor, but at $500 they are professional level items, unless you can get a surplus EAB.. those would work great.

Any grit will work, but your pump/gun has a nozzle and the larger the grit, the larger the nozzle and the more CFM you need to make the same pressure. Generally 40/80 grit black beauty ($8 for 50lbs retail) is the cheapest/best way to go. So you could do a frame for a few bags... just recycle it.

Sandblasting is like painting.. there is no one quick easy way to get good results.. lots of variables to consider.

pfarber · Post by **pfarber** » Fri May 08, 2009 9:33 am

As for the large trailer compressors... forget it. You don't want to have that much media sitting around. Plus at those pressures/CFM you have little room for error. With the small shop compressor you have a more control.

Unless you already have a good compressor, job it out... it will take you $1k to get the stuff you need to do a good job in a reasonable amount of time.

kenperkins · Post by **kenperkins** » Fri May 08, 2009 5:41 pm

silica dust can be very harmful. OSHA now feels it's on the lines of asbestos so caution should be used. atleast use a resporator and a face shield.

years ago when I blasted my frame, I bought a cheap sandblasting pot from Home Depot, (Campbel Hausfeild) didn't hold much sand but did the job .trick is to have high volume of air and refill the pot often.

i used bags of clean construction sand # 2 I believe.

if you can't find a sand blaster company in your area check out the comerical painting companies, as they often do sand blasting.

idiocrates · Post by **idiocrates** » Fri May 08, 2009 8:39 pm

Thanks for all the great replies and advice. I think I know now why its been next to impossible to find anybody willing to sandblast my frame. I did find one.......a bridge restoration company....who would be willing to do it but all their equipment was currently out on a construction site so I kinda forgot about them. Today I found a guy who does a lot of masonary restoration and he was sandblasting a fountain when I drove up. He said he'd be willing to blast my frame so I think I'm going to take him up on the deal before he has a chance to change his mind!

Jim

DJ · Post by DJ » Fri May 08, 2009 9:31 pm

Check with big truck repair facilties that do paint and body work.

kenperkins · Post by **kenperkins** » Fri May 08, 2009 10:57 pm

thats great, however don't think about useing that sandblaster on sheetmetal parts,,it will etch very deep and it hard to fill prior to paint

ask me how I know