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FJ 432
07-06-2010, 01:54 PM
I found 2 1950's metal kitchen wall cabinets on line and they were originally pink. Probably in the 1970's someone painted over the pink with avocado green latex paint. Then in the 1980's or 1990's they repainted them with latex white.

I bought these for my garage and instead of sanding these down before I repainted them I took them to a sandblasting shop to save me some time. I only wanted the doors blasted because the cabinets themselves weren't layered/caked with paint. Having never done this I was anxious to see how it would turn out.

I got them back and they were warped badly!!!! It looks like they stuck a nozzle inside the opening of the hinges (hollow)and blew out the front and back side like an envelope.

Long story but here's my question. Does sandblasting cause this type of warping? Heat maybe. Did they use the wrong media? The metal was fairly heavy but maybe not heavy enough.

FJ_Mark
07-06-2010, 03:57 PM
Sounds like the blaster warped the panels. Where did you have it done?


I found 2 1950's metal kitchen wall cabinets on line and they were originally pink. Probably in the 1970's someone painted over the pink with avocado green latex paint. Then in the 1980's or 1990's they repainted them with latex white.

I bought these for my garage and instead of sanding these down before I repainted them I took them to a sandblasting shop to save me some time. I only wanted the doors blasted because the cabinets themselves weren't layered/caked with paint. Having never done this I was anxious to see how it would turn out.

I got them back and they were warped badly!!!! It looks like they stuck a nozzle inside the opening of the hinges (hollow)and blew out the front and back side like an envelope.

Long story but here's my question. Does sandblasting cause this type of warping? Heat maybe. Did they use the wrong media? The metal was fairly heavy but maybe not heavy enough.

MDH33
07-06-2010, 04:11 PM
It's not heat that warps it, but the media pounding the metal which causes it to bow outward due to the molecular structure of the metal changing due to the repeated bombardment. I'm sure some of the metallurgists can explain it better.

FJ 432
07-06-2010, 04:18 PM
I had it done at a shop that actually inscribes grave markers called Alpine Monument. They were close by my work and thought I would give them a shot.

So Martin, it changes the metal. That's interesting. I wonder if they used a different media like soda as opposed to sand it might have changed the outcome. I guess sandblasting is better left to heavy or heavier gauge metal. Thanks.

Hulk
07-06-2010, 04:24 PM
Did they mention the risk when you originally talked with them about the job? Have you contacted them and explained the damage?

Beater
07-06-2010, 04:29 PM
good luck getting them to cover anything, as they did nothing wrong. you basically planished them out of shape.

FJ 432
07-06-2010, 04:33 PM
Did they mention the risk when you originally talked with them about the job? Have you contacted them and explained the damage?

Yes they did. They said there might be warping. I don't feel they did anything wrong and I'm not trying to bad mouth the company. I asked them to remove the paint and they did.

I was trying to find out how the process of having them blasted made them blow out the way they did.

MDH33
07-06-2010, 04:33 PM
I had it done at a shop that actually inscribes grave markers called Alpine Monument. They were close by my work and thought I would give them a shot.

So Martin, it changes the metal. That's interesting. I wonder if they used a different media like soda as opposed to sand it might have changed the outcome. I guess sandblasting is better left to heavy or heavier gauge metal. Thanks.

The media used to sandblast granite for gravestones is usually very very abrasive and large particles of aluminum oxide. I doubt they changed out their media to something milder just for your cabinets. For paint removal on thin gauge metal, you would probably use something much milder.

FJ 432
07-06-2010, 04:35 PM
good luck getting them to cover anything, as they did nothing wrong. you basically planished them out of shape.

I see said the blind man....... so the process stretched the metal...

FJ 432
07-06-2010, 04:37 PM
The media used to sandblast granite for gravestones is usually very very abrasive and large particles of aluminum oxide. I doubt they changed out their media to something milder just for your cabinets. For paint removal on thin gauge metal, you would probably use something much milder like soda.

That is something I suspect and I wondered if a gentler media would have made a better outcome. Thanks.

60wag
07-06-2010, 05:28 PM
On the other end of the spectrum is shot peening. Using larger media is an effective way to work the surface of metal. Some leaf springs are shot peened to reduce surface stress which reduces the formation of cracks and improves the life of the spring.

farnhamstj
07-06-2010, 07:54 PM
I use 60 grit Aluminum Oxide to sand blast memorial engravings in my park. There are all different blast materials with different abrasive qualities, similar to sand paper. Roughly 90psi-125psi is used. If the metal on the cabinets is thin I can see how it would deform them.

SteveH
07-07-2010, 09:46 AM
Also - the worst thing to sandblast, from a distortion perspective, is a big flat sheet of metal. You'd have been ok, I think, if you had them sandblast a curved front FJ40 fender or something that had some inherent strength from its shape.

FJ 432
07-07-2010, 01:38 PM
I appreciate all the comments. I went into this project thinking that sandblasting is all the same with one exception, different media. I will know better the next time.