quick sandblasting media question

[KYZAAC]

i built a pressure blaster a few weeks ago, out of an old 8 gallon compressor i had. i couldn't find sand to use,so i ended up trying play sand, then i found blasting media, can't remember what grit but its ruff and the only stuff they get in.

anyways, im doing an sr swap and i have the engine bay cleaned, what would be the best media to blast the bay? my cousin is coming home so im getting her to stop in princess auto, im getting some crushed glass and walnut shells, what grit sand would you recommend?they also have: aluminum oxide, bainite steel shot, ebony grit abrasive.

i heard some ppl blast engine blocks with walnut shells, but im not taking the chance, but would the walnut shells be ok to use for some parts?any input will help

[breadbox]

don't use play sand, it works but bad for breathing.

Most people just use de greaser or wire brush/wheel. Why blast your motor? I'd blast small parts you can take off, like rusty suspension parts.

[mudvayne9790]

he wants to blast the engine bay not the motor

[spank044]

I used a combination of medium grit glass and fine sand. Then whatever I swept off the ground when I went to reuse it. I do recommend using a quality respirator and face shield with a good covering of clothing.

[OM3GA]

Definitely wear a good face mask and respirator. I like walnut shells for blasting things like intake manifolds mainly because it actually bounces around in the runners and cleans it all up really nicely. On the outside of that stuff glass bead works out great you have to be thorough about cleaning the stuff out though you DEFINITELY do not want any blast media going in your engine Period.

Back on your topic, im not sure how walnut shells would work on the outside or how much paint it would get off if you are trying to get paint off to? Or do you just want it really clean haha.

[KYZAAC]

only reason i used play sand was because i picked up a siphon blaster and couldnt find anything else to use. i know how bad silica is, my grand fathers funeral was today, silicosis from the coal mine, never smoked a day in his life

"spank044" did the mix work alright? did you do any prep b4 blasting? im prob gonna give it a lil shot of break cleaner or something, i haven't used the pressure blaster yet, but i wasnt to impressed with the siphon. im going to try to reuse what i can too, i gotta pull the car out of the garage, i was thinkin on laying a tarp down then using a shop vac to get back what i can.

"OM3GA" yea im trying to get paint off, i always worked on bikes so im kinda just wing'n it here. im trying to find outt what media is best for what diff applications, when i first googled and seen walnut shells i thought it was a joke hah

i'll think i'll try the combo for the bay, and glass should be alright for the odd parts?

[OM3GA]

Yeah glass should be fine on the odd parts. Just make sure you THOROUGHLY clean and blast them with air afterwards.

[spank044]

I used a pressure washer to get the big stuff then just went at it after it dried. The med grit glass was about the size of Nerds candy, but with jagged edges. The mix worked great, the glass broke the paint and rust then the sand smoothed it out. Then the little rocks and whatever else was in the driveway shot right through as well. My tank has a passage to get the pressure to the top of the tank and then gravity feeds the mix into the pressure stream and out the nozzle.

[KYZAAC]

i made my blaster the same way, did you actually mix the 2 together or use the glass first then the sand?

[AZhitman]

You're not gonna have enough CFM's to do anything with a small compressor.

You need a minuimum of 7 CFM's at 90psi or you're wasting your time, and I haven't seen any 120v compressors move that kind of volume.

Maybe I'm missing something, I dunno.

BTW, I'm experimenting with my new soda blaster this weekend.

[Steveka24det]

strip the engine bay , go to local parts store grab gallon of simple green , some scotch brite pads and get scrubbing it takes time but you will be more pleased and less mess

on a side note a high pressure blower attachment for the compressor will help blow all the dirt in the seam sealer away

take look at the Ls 240sx going nuts thread that be mine and i just got done with my engine bay

[KYZAAC]

You're not gonna have enough CFM's to do anything with a small compressor.

You need a minuimum of 7 CFM's at 90psi or you're wasting your time, and I haven't seen any 120v compressors move that kind of volume.

Maybe I'm missing something, I dunno.

i have a 60 gallon husky compressor wired 220 direct to the fuse box, 12.9 cfm at 90psi, not the best, should work tho, might have to let it build up every few mins i woulda liked more cfm but just kinda grabbed it when i was at home depot,

the blaster is made from a 8 gallor compressor, im just gonna feed it air from the compressor

Compressor

Nozzle I Rigged up

And the blasterits all rusted from testing for leaks, i had a release valve threaded in and it was a slow leak, snapped when i tightend it so i just capped it off, holds 125psi np now im going to clean and paint with a spray gun for practice, im running copper piping in the garage now. so hopefully i'll have it blasted this weekend.

strip the engine bay , go to local parts store grab gallon of simple green

i have simple green, stuff works unreal, engine bay is stripped, i might throw a wire wheel on the grinder and get what i can then blast, i dunno, we'll see

[crakin]

pics when your done man.

[spank044]

i made my blaster the same way, did you actually mix the 2 together or use the glass first then the sand?

They started off separate, but after using it all a few times it slowly became one mess. I used a 110v 20 gallon compressor and a 5hp 20 gallon with my pressure pot and I was only able to shoot sand for about a minute then it built back up in a minute.

[AZhitman]

i have a 60 gallon husky compressor wired 220 direct to the fuse box, 12.9 cfm at 90psi

In that case, this is the sound of me shutting up.

You're more than set - Blast away, brother!

[motoman399]

hey can you briefly explain how you made the pressure pot? i have never seen how one works, and i have a spare tank laying around. thanks and i would go with a fine grit walnut shell, but i have no experience with walnut shells, just heard good stuff about them.

[KYZAAC]

hey can you briefly explain how you made the pressure pot? i have never seen how one works, and i have a spare tank laying around. thanks and i would go with a fine grit walnut shell, but i have no experience with walnut shells, just heard good stuff about them.

i just got a bag of crushed glass and walnut shells yesterday, just finished running the copper piping in the garage, needs a few drain valves and the air dryer and water seperator hooked up and i should be good to go.heres a quick write up of what i did, you can do whatever way u want tho.

its actually very easy, this is pretty basic. I'm terrible at explaining things, but i'll try.

Short version - Weld a 2" nipple or bigger in the top. Weld a 3/4" nipple in the bottom, look at the pic

what i did - i cut the top off the tank a few inches down, then cut a 2" hole in the centre, ( just drilled a hole and used a die grinder stone to get the right size), welded in a 2" nipple, welded on both sides of the cut off top. there are alot of better ways to make the filler port but i chose this because i had the material laying around. If doing this way i would recommend at least a 3" nipple. (in case something falls inside, gets plugged etc. You can get your hand in there (you could probably get away with just cutting a hole for the nipple, I removed the whole top because i was planning on doing it another way)

-On the bottom, i welded in a 3/4" nipple

-Now you need some way to get air into the tank. Threre were a few threaded holes already in my tank from the compressor, but you could drill a hole and weld on a nut, just make sure everything is air tight. Mine was about 6" from the top. I had another nut beside it i used for a pressure gauge, and one on the opposite side i used for a release valve, the release valve was leaking and snapped when i tightened it, the drill bit snapped while drilling it out, so there was a bunch of s*** in there and i couldn't get my hand in to get it out because of the 2" top nipple, thats one reason i recommmend at least a 3"

Then start running the pipe. I just picked up a lenth of 3/8" pipe from a plumbing wholesaler , i ordered a pipe threading kit a while back that works great. So I could just thread all the nipples i needed. (no one in my area ever has what im looking for, if you can get what you need from a shop/store it might be easier for you)

-I threaded a 3/8"x1" nipple and screwed into the tank (side of tank, near the top)-then thread a Tee To the other end of the nipple-Another 3/8" nipple threaded to the opposite side of T-Thread a Ball Valve to the 3/8" nipple-Thread a Male Quick Connect, into the ball valve (for air hose to connect)

You can use whatever size pipe, fittings, valves, etc. May require reducers, to connect pipe to valves etc.

The bottom of the tank, the 3/4" nipple was welded in earlier - I threaded a gate valve on the nipple.. My gate valve was 3/4" but you could use whatever size ya want .-now I need a reducer to connect the gate valve to the rest of the piping, i used a 3/4" male to 3/8" female Reducer-attached 3/8" nipple to the reducer-the other end of the nipple attached to a T-Okay now one side of the T Is going to be where you hook up your hose for blasting(I used a nipple, ball valve, and a hose connector. Then used a 6 foot piece of old rubber compressor hose.)

-The other side of the T (on bottom) needs to meet the piece coming down from the T (top) By the upper ball valve (look at pic)Take some measurements, remember to leave room for threads, i think 1/2" each side will do. I put a 1/2" union on, saves alot of hassle if it needs to be disconnected.

Once its all finished, fill it up with air, and check for leaks. I put 125psi in mine and had water in a spray bottle. If you find a leak just grind the part of the weld that was leaking and lay a bead.

I used a stick welder with 3/32 6011 rods, but any welder you have will work





-The air goes in the tank, and down the pipe to the valve by the hose, so there is pressure to move the sand to the gate valve then when you want to blast open the ball valve by the rubber hose and blast away.

hopefully that makes sense, i've never used or even seen a sand blaster before, just went off a pic, i'll take few pics of the nozzle/gun i made and explain that, i ordered 2 ceramic nozzles from princess auto, one was 1/8, the other was 3/32. im late for easter dinner with the family tho. do that later
Modified by KYZAAC at 6:22 PM 4/4/2010