Abrasive blasting

[Adam Preble]

I have some metal cabinets I wish to repaint. I think the last layer on them is a powder coating, which is very stubborn. I have been using wire wheels with my metal grinder, but I can't access all the areas with it. I was wondering if this is a good excuse to get into abrasive blasting.

I have a pretty decent air compressor, and I have seen some attachments that work with one. I just wonder overall how they do compared to a dedicated unit. I would prefer not to get a big unit since the compresser clutters my garage just fine.

What concerns me more is safety. I know I should get a hood, but do I use a respirator too? I assume regular old painting masks aren't enough. What is sufficient to protect myself?

I suppose the hidden question here is how well very basic abrasive blasters do against powder coats. If it can't make a difference, then I suppose it's not worth it for my needs.

[hallerb]

unless you have a 40HP compressor sand blasting with any media will take many days, of hot grueling work.

trouble is its really slow and very dirty, plus theres a good chance of lead in the original coating.

so wear a respirator!

go buy a cheap sandblaster at home depot under 30 bucks, spend a few hours doing a one foot square area, and come back here to report.

you need a sandblaster used to prep bridges for repainting and note how long that takes..........

[Bob F]

I have one of the really simple blasters - just a hand held gun, a rubber hose, and a metal "tube-in-tube" for the sand pickup. It does a reasonable job at 150 psi. At 90, it's a lot less effective. The sand size does affect performance also.

If you've got paint so well bonded, why remove it?

Bob

[Adam Preble]

"Bob F" wrote in news:NO6dnRMK9-IWIq7anZ2dnUVZ [e-mail]:

The question came up a few times so I thought I'd address it in the last one I read in the thread. The powdercoating isn't perfect since I'm getting some rust on the edges. The real killer is those edges on the back side.

I will probably butcher the description, but the sheet metal on back bends in to close it off. So you get these 1" flags all around the perimeter. In the little niche created by this, I see a nasty amount of rust and crusty paint; the powder coating looks to have suffered there too.

We tried painting over the powder coating, but it takes many coats and still wants to flake straight off. Perhaps I could just sand the snot out of the powder coating, but I'd rather start from the metal if I could.

I was planning to take the larger of the two cabinets out by the patio to store my accumulating outdoor cooking supplies. I wanted to paint it a nice red--a very tough color to use but I think it would look nice.

[Cshenk]

"Adam Preble" wrote

I follow you. They 'likely' get all the rust out of that joining area before powdercoating so it 'grew back'. On ships which are always (obviously) exposed to salt air, we have to constantly battle such rust problems. Even internal to the ship, it comes out over time.

The biggest difference you'll note in my posts on this, is I am used to high-end sanding gear. Thats ok. It sounds like others who have experince with the stuff you have, say it ill do the job but slower.

Please though if you take nothing away from my posts, do take me seriously about the safety gear. I have seen so many people get hurt doing this when they took shortcuts because they thought it would be 'faster' or something. A month in the hospital and blind in one eye for life, is not saving time. The proper gear is quite inexpensive.

The goggles you need are about 3$. They fit over glasses fine if you wear glasses. If they get scrateched, thats a sign of what would have happened to your eyes if you hadnt been wearing them. I actualy have 3 sets here at home. 1 for ech of us, but the 3rd is really a spare as we don't let our

13YO near when we are working something that takes them. Get a spare set so you arent tempted to go without for that 'just a moment more' when you find the pair you were using are scratched. Yes, they fog up if you sweat alot, but that just takes a moment to cool off and its probably break time by the anyways .

For the breathing, use the right mask. I mis-stated the vapor kind earlier, you can use the lessers ones for high dust and particles just fine. (The vapor kind handles that too). You do not know exactl what is in the type of powder coating, so it pays to wear the mask. Some of the coatings are long term exposure carcinogens if flying about as dust.

Grin, get the rusty parts to bare metal if you can. If there is any rust at all left, it will come back. Then, prime all bare metal with a preservative meant to go on metal and prevent rust. I am used to 2 types, one is red and the other is green. They both work just fine. If you have trouble getting into crevices, try a thick application of something called 'Naval Jelly'. It can and has worked well for those really hard to reach little bits. You will need heavy duty rubber gloves (and i dont mean the latex ones for washing dishes) but it applies fast and then you come back the next day or so and the rust often just washes off.

Its used when you hit those wierd angles where no matter how you try, the sand from the sandblaster hits you in the face.

If it's easier, sand the snot out of the areas *not* rusted and that should work.

Ah, makes sense! Hey, if it's a covered patio and the cabinets arent in the direct sun, the red should last quite a while. If you go for a sort of 'brick red' it will last even longer.

I have the same problem with nt enough cabinet space in my kitchen. We've been looking at garage cabinets but we do have a huge porch so you've given me some possible ideas there. Thanks!

[Asmodean]

SNIP

I use my 9 HP with 60 galaon verticle compressor. I have a smaller one out in the shed. It is used for my positive air flow hood. No resperator needed that way. I then get the Black Magnum Sandblasting medium from Menards and blast away. Stripped and car trailer frame in about an hour.