Sandblasting tubing

[Leenicklas]

Now that I have transported my project from Texas to my hangar in Tulsa, I'm ready to clean up the fuselage tubing and otdher parts. Is there a "poor boy" way to do this, or do I buy a sandblastder?? How big, How much pressure; can you recover sand when blasting something as big as a fuselage.

[jdoran]

Re: Sandblasting tubing

Hi Lee,

Consider renting (or buying) a power washer and using a sand injector. This allows you to suck sand out of a bag or 5 gallon bucket, and injecting the sand right where the high pressure exits the nozzle.

It's a poor man's sandblaster, and it works good. If you buy the sand injector attachment, only buy the one with the carbide nozzle. it costs about $150 to buy the setup.

We make this sandblast enclosure built on a trailer,

http://www.centrevilletrailer.com/customFabrication/sandblast-containment-trailer.htm

----but you could rig up some tarps or plywood walls for a temporary enclosure.

Use a power washer that has a minumum of 3,000 psi and 3.5 gallons per minute of flow (not a homeowner unit)

Buy some phosphate wash at Home Depot and spray it on the tubing as soon as you finish cleaning the metal. It will prevent rust from forming for a week or so until you get it primed and painted.

[Mark Julicher]

Re: Sandblasting tubing

You can poor boy it with a suction tube/bucket of sand style sandblaster, but you will need a lot of air and a lot of patience. The air MUST be dry or you will clog the hoses every 5 minutes.

Better is to rent or buy a pressure pot sandblaster that holds about 50 lbs of #5 blast sand. You still need a LOT of DRY air. A 20 gallon compressor will not hack it.

First class is the rig jdoran calls out. In my dreams.

[Hank Jarrett]

Re: Sandblasting tubing

I went out and bought a pressure sand blaster. You could easy make back the cost of the equipment by charging for all the little things people will ask you to blast for them. DON'T!!! The EPA guys have a habit of hearing about anyone who is sand blasting and "dropping by" and collecting a sample of your used blast sand. If you blast something with lead based paint on it your sand will be contaminated and you can't imagine how much it costs to get rid of the used sand once it is labeled "hazardous waste". If they find ANY contaminant in the sand, they call ALL of it contaminated and they get pretty Draconian about it.
I sold my pressure pot blaster after the fuselage was done for what I paid for it and got a Harbor Freight siphon blaster (CHEAP) that I mounted in a plywood blast box for all the little stuff.
The blasters are really not that expensive, but you need a MINIMUM of a high capacity 5HP compressor to drive them. If you work it right and have enough electrical power available, ganging a 3HP and a 5HP works great and when you are through you have a 5 for any air tools in your shop and a 3 for the garage that will handle almost anything at home.
My blast booth was made of heavy polly duct taped to PVC tube hung with safety wire in the hangar. Only real problem was the sand gets EVERYWHERE inside the booth (anatomically). I wore full coverage paper suits taped at the wrists and ankles with all the openings sealed. A taped up hood over my head with GOOD EYE PROTECTION and you need a HOSE RESPIRATOR. I still got a butt crack full of sand, and the elastic on your underwear will become unbearable.
If you breath in the fine dust from blasting you can DIE from Silicosis and you haven't felt pain till a grain of that sand gets into your eye and the guy outside the booth has to blow you off (reach through the door flap, he doesn't need to breath the dust either, and he needs a good cartridge respirator and eye protection at a minimum too). You will have a lot of fun cleaning the fine dust out of your ear canal for days too.
Once the steel is blasted, you need to cover the metal IMMEDIATELY. I wiped down the sections that had been blasted and cleaned everything getting a coat of primer on. I primed past where I had blasted and the next day blasted another section taking off the primer from the prior day for several inches. It took a LOOOONG time and was a miserable job, but the fuselage came out great.
Now for the bottom line. Check out the professional blasters in the area. It only costs a few hundred dollars around here to blast a fuselage and some of the places will even anti-corrosion coat and prime it as soon as it comes out of the blast booth. I would NEVER do it again.
Hank

[Guest]

Re: Sandblasting tubing

I use black beauty abrasive instead of sand it is a crushed slag product there are other brands of crushed slag available and I am told that it is not prone to cause silicosis however I cannot prove that I just heard it and believed it.

[N96337]

Re: Sandblasting tubing

I took the last 2 I did to a guy that soda blasted them for me. I LOVE IT!! That's the best money I've spent in a long time and I wasn't digging sand out of myself and everything else for weeks. The finish is wonderful and it wont flash rust like sand blasted tubing does. If it has any disadvantage, it's that it's a bit more gentle than I usually like, and wont blow through any tubing unless it's rusted really bad. Soda blasting is so much more "user friendly" than sand!
John

[swoeric]

Re: Sandblasting tubing

Well Lee im not too far from you up here in on grand...Aluminum Oxide or soda...pay for an experienced guy to do it.... there are several folks in or near tulsa...call sot abrasives they will know who in town has a booth...as for the epa concerns...it is called a tclip test and the concern is chrome in the paints...but it must be water soluble...so if it is dried in paint it is considered encapsulated....most blast media test clean.....60% of what i shoot is chromated...therefore 60% or more of what i have stripped is chormated....give me a call when you have sometime and i can help you put together a plan to remove the finishes on your parts and get them turned around to like new shape...i'd love to see the project Eric 918 740 0972 tulsa number or 918 786 6111 day time just ask for me

[Hank Jarrett]

Re: Sandblasting tubing

Drude,
I have a bag of "Black Blast" from Virginia abrasives sitting in the garage right now. It does NOT cause Silicosis, but you still wouldn't want to breath the dust from it unless you want to be immortalized with your name on a new lung disease. There aren't people dropping dead from it so it looks like it is a LOT less damaging than sand. The thing I like about it is it is much less prone to clumping in higher humidity. Moisture in the air was always clogging up my blaster with sand.
Eric could be a real help here. He is HANDS ON, where I was a safety engineer who decided to try it himself (read that amateur who substituted lots of sweat, time and work for skill to get it right). When Eric says hire a professional, listen! Doing a fuselage is just way too much work for one of us to do and we don't have the experience and equipment to do it right.
That said, I DO have a blast box and wouldn't give it up. I have tried a couple of times to convince Ray (the Swift Guru tribe member) to convert one of our boxes to aluminum only and the other to steel only. Soda is GREAT on aluminum and very low toxicity but really slow on steel. NEVER BLAST STEEL AND ALUMINUM WITH THE SAME MEDIA!!!! The media picks up microscopic bits of metal and drives them into the other metal. The corrosion under the paint makes a mess. It is like grinding wheels, one wheel for each metal and DON'T MIX THEM!
Hank

[Guest]

Re: Sandblasting tubing

Thanks Hank for the info.

I have done 3 fuselages in 30 years. Not too many. The first one I did inside a garage with hanging tarps and resused the media.

The second 2 I did outside on a smooth clean hard surface and reused some media.

I agree I don't like that stuff in the air I breath (or my clothes & orfiices) so going to outside was an attempt to surround myself with cleaner air.

I think it helped.

If I ever do one again I would like to hire it out. What is the typical cost? Anyone know?

Dave

[Pilot78]

Re: Sandblasting tubing

I have the Harbor freight blast cabinet and portable pot.... I use them for small projects and works great. I have an 80 gallon compressor with an a water separator and have never had any problems. However, I took my fuse to a local guy here that has done many vintage planes and old cars, I dropped my fuse off on a Wednesday and picked it up on Monday and wrote a check for $300. It was a bit of money but there is a lot of tubing there and I got mine back without a spec of old paint on it. I was really happy with his blasting and glad I didn't have to spend the hours flipping the fuse around to blast all that tubing. I built a spray booth in my hangar and I had it primed and painted within 2 days so it didn't rust. My 2 cents, attached are a few pics.

Brian
SLC-UT
TF#1023

[Richh2only]

Re: Sandblasting tubing

Nice looking paining setup, I really like your hangar floor. You sort of look like Charlie Sheen in the photo with the painting mask.
Are you using an epoxy primer / paint? If you are it is recommended to use a fresh air breather as a standard mask does not remove Cyanoacrylates in the paint mist.
No sense screwing up your lungs so you can not enjoy the fruits of your labor.
Happy Flying

[Hank Jarrett]

Re: Sandblasting tubing

Cyanoacrylates are used in super glues like Eastman 910 (one of the first). I think you are thinking of Isocyanates which are used in paints like Polyurethanes (like Imron).
Epoxy paint is a copolymer made up of the base "resin" or "compound" and a "hardener" or "activator". The harmful chemicals in Epoxy paint are usually bisphenol A and glycidic ethers. Bisphenol A is what causes the epoxy resin to form. In the body it acts like a hormone and settles in the endocrine glands where it disrupts the glands functions. Glycidic ether is a dense molecule solvent and replaces the oxygen in the air of a confined space causing suffocation.
Epoxy is NOT something to be treated lightly, but it is a lot safer to use by us than Polyurethanes. Isocyanates accumulate in the body over time (you can't excrete them out) and when they reach a critical level, they sensitize you and you die. With Epoxy you need to follow the safety sheet carefully and you will be OK. The safety equipment is available at your "Home Airplane Depot". Polyurethanes ( the short chain Isocyanate types used in a lot of aircraft paints, not the stuff from the hardware store) require you to have NO skin exposure and NO breathing of the fumes. FULL "Space Suit" paint suits with hosed in outside air. I know people use it with a breeze at their backs, but they are IDIOTS and one day they could DIE. There were people who DIED on the Naval Station from exposure to short chain Isocyanates while I worked there. I spray Epoxy in my garage. I like Epoxy. It is TOUGH, chemical resistant, flexible, inexpensive (OK, relatively) and easy to work with. Most of all, it is SAFE if used right and I don't have to get paint on my space suit. ;-)
Hank

[Guest]

Re: Sandblasting tubing

I have the Harbor freight blast cabinet and portable pot.... I use them for small projects and works great. I have an 80 gallon compressor with an a water separator and have never had any problems. However, I took my fuse to a local guy here that has done many vintage planes and old cars, I dropped my fuse off on a Wednesday and picked it up on Monday and wrote a check for $300. It was a bit of money but there is a lot of tubing there and I got mine back without a spec of old paint on it. I was really happy with his blasting and glad I didn't have to spend the hours flipping the fuse around to blast all that tubing. I built a spray booth in my hangar and I had it primed and painted within 2 days so it didn't rust. My 2 cents, attached are a few pics.



Brian
SLC-UT
TF#1023

Thanks for the info Brian, I would happily pay $300 for that blasting work. Dave.

[Guest]

Re: Sandblasting tubing

Cyanoacrylates are used in super glues like Eastman 910 (one of the first). I think you are thinking of Isocyanates which are used in paints like Polyurethanes (like Imron).
Epoxy paint is a copolymer made up of the base "resin" or "compound" and a "hardener" or "activator". The harmful chemicals in Epoxy paint are usually bisphenol A and glycidic ethers. Bisphenol A is what causes the epoxy resin to form. In the body it acts like a hormone and settles in the endocrine glands where it disrupts the glands functions. Glycidic ether is a dense molecule solvent and replaces the oxygen in the air of a confined space causing suffocation.
Epoxy is NOT something to be treated lightly, but it is a lot safer to use by us than Polyurethanes. Isocyanates accumulate in the body over time (you can't excrete them out) and when they reach a critical level, they sensitize you and you die. With Epoxy you need to follow the safety sheet carefully and you will be OK. The safety equipment is available at your "Home Airplane Depot". Polyurethanes ( the short chain Isocyanate types used in a lot of aircraft paints, not the stuff from the hardware store) require you to have NO skin exposure and NO breathing of the fumes. FULL "Space Suit" paint suits with hosed in outside air. I know people use it with a breeze at their backs, but they are IDIOTS and one day they could DIE. There were people who DIED on the Naval Station from exposure to short chain Isocyanates while I worked there. I spray Epoxy in my garage. I like Epoxy. It is TOUGH, chemical resistant, flexible, inexpensive (OK, relatively) and easy to work with. Most of all, it is SAFE if used right and I don't have to get paint on my space suit. ;-)
Hank

I have never used epoxy ot polyurethane.

Can you brush epoxy on?

Dave

[Hank Jarrett]

Re: Sandblasting tubing

You can brush most epoxy, but it sprays fine from a $3 Harbor Freight airbrush. I primed and painted my whole 45 fuselage frame with cheap "model" airbrushes and it worked great. The fan is about 2" wide so there was very little overspray (move in a little as you get practiced and there is almost none). I used VERY LITTLE primer and paint and got great coverage. Everybody laughed at first till they realized their "real" spray equipment put 80% of the paint into the air and was no faster than mine. That and when I don't get my sprayer clean enough, I throw it away and open another one. When epoxy dried in theirs, they sat and cried with their face in their hands.
The air brush is pretty useless for open areas like dope on fabric wings, but great for small parts and tubes. I bought one of the cheap HVLPs for the Dope and it worked great too.
Hank