Sandblasting

[Allen Sutphin 705]

Jim, or anybody else for that matter, what media do you use in your sandblaster? I tried walnut hull media but they wouldn't even scratch the paint and the glue that was used must be from NASA since it is the hardest stuff I've ever seen. MEK, Acetone or anything I've got won't cut it. Pure sand will barely rough it up.  Its not poly-tak so it must be some kind of epoxy two-part glue. No wonder it weighed over 700 lbs empty weight.  Add 3 layers of fabric (yes 3 layers) and the vinyl coating and this thing was a hangar queen, looked great, but never flown. I weighed the fabric when I removed it and it was over 50 lbs in fabric and paint alone. Yikes!

[chopndrag 226]

Could be powder coated of so I use aluminium oxide to blast it . 

[Allen Sutphin 705]

Don't think its powder coating. I've seen that many times and this stuff is tougher than Chinese math. But I will try the alum oxide media. I even used the old trick of heating it with a torch prior to sandblasting to soften the paint, no cigar, just turned it darker. May just scuff it up with sandpaper and a wire brush and paint over it as a last resort.  Just would like to clean the glue off first.  Thinking about trying the Stewart System this time instead of poly-fiber. Have never used it before.

[Dusty 126]

Powdercoating is one of the hardest coatings to remove.Unless you have access to a commercial blaster (200+cfm)you will have a real battle.The grit I use is sold here as speedblast  garnet or D+ grade but the cost for the amount you us as a "blast to waste" will really make you hurt.Do you have assess to 30/60 grade crushed glass?This will be slower but the next best thing.Someone on this forum once suggested gasket stripper!Epoxy paint usually fries powdercoating so as an experiment soak a rag in epoxy thinner, wrap it around some powder coating possibly followed by some clingwrap to keep the solvent In,

have fun,keep smiling.

[TJay 1041]

Powdercoating is one of the hardest coatings to remove.

Use to be at least.

I had my wing struts powered coated after I built them. Then I went to scuff up the back to glue on my wood struts I could sand the paint right off with out even trying. Everybody keeps getting more expensive and the quality keeps getting less.

[Allen Sutphin 705]

This was built in 89' so its possible that it is the original factory powder coating. Add many, many layers of paint and then a cheap coat on top and anything is possible. I did manage to remove the cheap top coat so I may be able to recoat the original coating with a good primer/sealer. From close inspection there is no rust or corrosion on the airframe. It evidently has been in a dry hangar all of its life and not flown very much at all.  Oh, I will succeed just may take a little longer, but its going to be a long winter anyhow.  A like new remanufactured model 2 built light and right could be the perfect aircraft for the type of mountain flying I do. I rebuilt a Funk from the data plate up and this is no different.  I did like the gear arrangement on the funk, you could drop it in from 15 ft and it would stick. Not that anybody would ever do that, though. We all make perfect landings, don't we?

[chopndrag 226]

Gotta use good powder just like in the 80's .... I have a account with tiger and use there industrial coating on the airplane stuff and it's damn near bullet proof plis I take pride in my work which a lot of people don't anymore they just want that money.

[1avidflyer 1983]

The sand blast media I used is medium or fine grit garnet, made by Black Diamond.  Came in 80 lb bags and was under $10 a bag.  With the big blaster, I also used silica sand that you can buy in a lumber yard.  I was using a huge sandblaster though, and it works 10 times better than a small one from Harbor freight that you run off you garage air compressor.  When I've taken off powder coating, I burned it with a propane torch, and then it came off a lot easier.  JImChuk

PS  I went to add the pictures, and see I didn't post the whole message.  Alshimers???  I forgot about the sandblast issue, till after it was dark.  Had to use a flashlight to get these pics.                          oo

Edited 6 Sep 2018 by 1avidflyer

[chopndrag 226]

I completely forgot about black diamond that's hard to find anymore around me. There is a shop that does nothing but sandblasting and that's what he uses. I send him the crap I don't want to deal with amd always get a good deal. Makes my life easier and it also ends up cheaper when I powder coat something big. It takes him 20 minutes to knock a chrome rim down to bare metal vs a hour and tons of headaches for me. Well worth it to pay for it.

[Allen Sutphin 705]

Today I found a commercial blaster at a tool shop that was going out of business and it was new. Got it along with a few bags of Black Diamond media for a good deal so I should be good to go.