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Metal prep in non seen areas

#1
In areas that do not get seen and are hard to get to are my only options sandblast or Ospho?
I'm not doing a complete restore but want to keep future rust under control.
I was thinking Ospho, neutralize, epoxy, and paint.
I know some of the flat places I can sand but the rest?
Such as these areas. 20190309_112628.jpg 20190309_112637.jpg 20190309_112634.jpg
 
#3
no matter what you do there, it will rust again. The lesson we have learned is that if you think you will save a joint because the metal is strong enough and has no holes, it will be the first place that ends up rusting back thru. You might as well just sand it as good as you can and epoxy it, then get mad that the epoxy was no good because it rusted again. Getting those spotwelds cut and cleaning the flat surfaces that are welded is what stops that rust from coming back, and then, they are no longer hard to reach areas.
 
#7
no matter what you do there, it will rust again. The lesson we have learned is that if you think you will save a joint because the metal is strong enough and has no holes, it will be the first place that ends up rusting back thru. You might as well just sand it as good as you can and epoxy it, then get mad that the epoxy was no good because it rusted again. Getting those spotwelds cut and cleaning the flat surfaces that are welded is what stops that rust from coming back, and then, they are no longer hard to reach areas.

Well I understand I can't stop it without some major work. I've not got the skill to weld, the money to pay for it and the patients. Just hope to slow it down a little more than just painting over it. But I know what your saying.
 
#8
No I didn't know if the area was too large for those.
Depends how you look at it, yes you could say you want a bigger blaster and you knock it out pretty quick. Bigger blaster more volume, more air, the pro's have it down to keep the mess down I would assume. For me, well I'd have a mess, I know me.

Smaller version hand held from HF, is slower but less mess. I like this and for that size of an area in your pic.

There isn't really a right answer on this when it comes to you and your style. When I looked at your photo right off I'm thinking about pulling out my small blaster, but it is a pic and pics can be miss leading.
 
#10
Someone gave me this Central Pneumatic pressure blaster from Harbor Freight. I had to replace the Deadman valve with a ball valve within a couple of days.
IMGP0007.JPG

I also have one similar to this siphon style gun:
https://www.amazon.com/ABN-Sandblas...hon+blast+gun&qid=1552687975&s=gateway&sr=8-8

It is getting the job done and yes very messy. Notice the floor in this next picture.
I wear my respirator underneath this cheap hood:
IMGP0009.JPG

I buy the clear plastic shield replacements in a 25 pack because seeing what you are doing is a must.
Also buy the ceramic tips 10 at a time.
Using crushed glass 40/70 grit which gradually breaks down during recycling to a fine dust that blows away while spraying.
 
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#12
The ceramic nozzles gets bored out from the media, so need to be replaced rather often. You may want to invest in a tungsten carbide nozzle. I bought one of these for my harbor freight blaster like the one shown above.
https://sandblast-nozzles.com/shop/tl2-series-tungsten-carbide-nozzles/
I will add that as the nozzle hole wears larger it will draw more CFM from the compressor. The compressor will cycle on sooner and depending on the capacity may never catch up. Important to size the nozzle to the compressor.
I did the same and put the carbide nozzle in the cabinet which is a siphon system.
 
#13
they have a trigger gun that looks like a garden hose spray nozzle with a hose that goes into the bag or a bucket you can find for 20 bucks online. Those worked best for me. I bought the cadillac vacuum system to do spots, they are nice if you can find one for a deal, but you pretty much end up with as much sand on the floor as the "bucket" blaster unless you are just doing flat surfaces. Its not saying you cant combine a shop vac when using a spot or bucket blaster. The nozzles depend on what you are using. I mostly use black beauty to blast powdercoat off of parts and those require boron carbide to last longer but still get eaten up. If you stick to garnet based stuff, it takes longer. You also prevent some warping once the nozzles wear out.
 
#14
I picked up one of the guns with a hose on it. I first tried it with some multipurpose sand I had, worked OK. I then got some clean play sand and filtered it thru some screen. This was the result. I think I can live with that in the areas I plan on using it. If I need to get it perfect I can pick up some other media. I need to drain my tank and hook up a dryer, I could see some moisture at times.
Thanks for everyone's input.

20190329_174900.jpg
 

Chris_Hamilton

Trying to be the best me, I can be
#16
First off don't use sand. It contains silica which is not good at all for your lungs. There are other reasons for not using it on sheet steel but that is the primary one. Use either crushed glass (preferable) or "black beauty". Google "black beauty media". Either one is as cheap as sand and does not have silica in it.
Going back to your original post, looking at the pics that type of rust is pretty common and not bad at all. If you clean it well and apply epoxy properly it will last.

Read about silicosis here:https://www.google.com/search?clien........0....2j1..gws-wiz.......0i71.R1CaHU6IuGg
 
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