Sand Blasting Q?

[cypress_33415]

Hey all newbie here,My buddy and I are rebuilding a 68 camaro.We pulled the fram to sand blast it.We used 200lbs of sand from home depot and didn't really get much done.Should we be using a different type of material for blasting other than sand?? Also I am using a hopper (40lb) it came with 3 different tip's. I used the biggest tip, but only put's out a pencil width stream of sand,Does this sound right ?? I was hopeing for more of a V patteren. Any help would be great..

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http://www.caswellplating.com/bbs/viewtopic.php?t=1482

Thank you customandsound!

[Fick]

Cypress,
Are you using a pressure blaster? Sounds like you may be using too low a air supply. Depending on the amount of rust you have, you may need a courser sand. Two hundred pounds of sand should do half the frame, in MHO.
Regards.
Fick

[XK120DHC]

Re: Sand Blasting Q?

Hey all newbie here,My buddy and I are rebuilding a 68 camaro.We pulled the fram to sand blast it.We used 200lbs of sand from home depot and didn't really get much done.Should we be using a different type of material for blasting other than sand?? Also I am using a hopper (40lb) it came with 3 different tip's. I used the biggest tip, but only put's out a pencil width stream of sand,Does this sound right ?? I was hopeing for more of a V patteren. Any help would be great..

Cypress;
I realize this post may be too late to help you, maybe it will help another..
"Home depot" type sand is great for mixing with cement.. it ain't worth a hoot for sandblasting automotive sheet-metal.. the "size" of the grains of sand range from too little to small rocks.. You probably did more damage to the metal with it than paint/rust removal..
You need to locate an honest-to-goodness "Builders Supply" (one that deals with contractors) and purchase the "finest" (in grit size) Blasting Sand they have.. usually this is "#4".. and even it is a bit too coarse.
As the other fellow asked, Are you running a "Siphon Feed" blaster (sucks sand from a bag or bucket)?? or a "Pressure Feed" blaster (sand under pressure in contained tank)??
If you are using a Siphon Feed type, throw it away.. you will ruin your compressor before you finish blasting a single front fender..
If you don't have a Pressure Feed Blaster, get one.. One that holds around 100lbs of sand.. you will need a "real" Five Horse (min), Twin Cylinder, Two Stage Compressor that will pump out a minimun of 17CFPM with AT LEAST a 60gal air tank.. 80 is better.. and you can't put enough oil/air filters in-line, either.. I use three. one at the outlet of the tank, a second at my regulator and hose connection and a third at the inlet of the Sand Blaster's Pressure Tank.. Water and Oil are BAD when sandblasting!
Once you have this set-up, you can begin to learn how to do sandblasting so you don't ruin the sheet-metal on the car..
First off, you need a "contained area".. all six sides enclosed, this includes a solid (concrete) floor, as you will be "recycling" the sand.. This is important..
Start off with about 80psi going into the Pressure Blaster, filled with new, unused #4 Blasting Sand and blast all your "hard parts"... suspension pieces (ft & rear), frame (if the vehicle has one.. a Camaro doesn't)... etc.. You want to run each bag of sand thru the blaster at least twice (filter the recycled sand before pouring it back into the pressure tank).. this "beats down" the sand, making it "finer".. This "finer" sand is what you want to cut the paint and rust off the Camaro's body.. The #4 just isn't "fine" enough to get into any rust pits.. and not cleaning them out WILL cause problems later!
Now the "tricks of the trade".. LOWER the inlet air pressure to the pressure tank to 50-60psi, keep the nozzle about a foot away from the sheet-metal and hold at a "low angle".. not 90 degrees to the work.. that will guarantee a heat warped panel.. Don't "hold" the nozzle in one place.. this builds up heat, as well.. Slowly move the nozzle across the panel, if you are lucky, a single layer of paint will come off with each pass.. otherwise, just keep going back and forth (long passes) and erode the paint and rust off the panel slowly.. You CANNOT remove ALL the paint in one pass.. DON'T Even Try!. You aren't finished blasting the panel until ALL the metal is an even dull gray.. and dark areas or missed paint is a problem waiting to happen!
DO NOT sandblast Undercoating, Grease caked parts, etc.. this only succeeds in forcing the tar and grease down into the pores of the metal.. It will let you know you screwed-up about a month after you finished painting the car!!
After you start sandblasting, especially after the panel is sandblasted to bare metal, NEVER touch it with your hands, again.. wear heavy rubber gloves during the blasting process and ALWAYS use "exam gloves" if you touch the bare panel.
Depending on the ambient humidity where you live, you may have between an hour to a couple of days to get that panel prepped and primed.. DO NOT wipe the panel down with Lacquer Thinner. DON'T think about blowing off the sand & dust with compressed air.. you WILL be just blowing a fine mist of oil and water on the bare metal!
Use proper "Cleaner/Degreaser" as recommended by your paint supplier, followed by wiping down with a quality Tack Cloth (some cheaper tack cloths wouldn't pick lint off a suit and do LEAVE fuzz behind!) then, using a quality HVLP Paint Gun, with an "in-line" oil/water filter at the base of the gun's regulator, spray the panel with a quality Epoxy Primer that is compatible with the sanding primer and top coat you plan on using..
Well, that's enough to keep you out of trouble, for a little while!

[BerkelUSA]

Re: Sand Blasting Q?

Cypress..

What kind of blasting setup did you use?

Pot Blaster?
Suction Blaster?
Cup Blaster?

and what size compressor is another good question..

220-volt?, 80-gallon?, 60?, CFM?, Hose ID's