Sandblaster Media

[i386]

Before I go off and do something stupid...

I have access to a Craftsman gravity fed sandblaster. I'm prepping my old boat trailer for paint. The old paint on it is already long gone. I just want to knock off the surface rust before I hit it with some Ospho/Primer/Paint.

The sand for sandblasters is hard to find around here (and expensive when you can find it). RSC used to carry it but they no longer rent the equipment due to safty concerns. Anyway, my question is why can't I use regular "play sand" from Home Depot to knock that rust off. I know it needs to be dry but what else? I have goggles and respirator.

 

[Reel Poor]

Re: Sandblaster Media

What size compressor are you using?

The playground sand is not very course and would probably not do a good job, it would be veeeeerrry slow and with a gravity fed blaster my not produce result enough to wast time with.

The gravity blaster itself is going to be disappointing even with the #2 media, on a job that size.

 

[tommays]

Re: Sandblaster Media

I use good sand in my cabinet blaster and it is only good for removeing flux scale from brazing on the bicyle frames i work on


If i have to repaint one i have to use stripper and then do a light cleaning with the blaster

It would take 100 years to strip the paint with the sand




Tommays

 

[12Footer]

Re: Sandblaster Media

What they said.


A high RPM wire rotary brush is the best way to tackle surface rust. I use my blaster on small part surface prep. It werks great for that and parts with lots of knooks n crannies. But the volume of sand you would need is reason enough to get whatever is gettable with the wire wheel in a disk grinder or air tool, and THEN nail the rascal with the blaster for all the corners and seams.

 

[i386]

Re: Sandblaster Media

What size compressor are you using?

The playground sand is not very course and would probably not do a good job, it would be veeeeerrry slow and with a gravity fed blaster my not produce result enough to wast time with.

The gravity blaster itself is going to be disappointing even with the #2 media, on a job that size.

Not sure, but it's pretty big. It's a vertical tank with a 3-phase motor and compressor on top. The whole rig is probably 5 ft. tall. He's got a little sand in it now and it's pretty coarse. It does work. It's slow but it gets into places other tools can't get into.

I have a couple bags of play sand laying around. My concern is that it might damage the equipment or pose some health risk. If those concerns are no big deal then I might hit what I can with the wire wheel/sander and save the tight places for the sandblaster using play sand. That sound reasonable?

 

[tommays]

Re: Sandblaster Media

Any water in the air or blast media will clog up the unit


At the last place i woerked that did a LOT of blasting we switched to slag products like black beauty becuse it had no sicla (silicosus)

Even with and area setup just for blasting we went away from it as it was just a nightmare to control the mess with 2007 rules


Tommays

 

[Windykid]

Re: Sandblaster Media

You could seek a media blaster shop that may not charge much, or knock down the heavy scale with a brush and paint with rust nuetralizer, then regular paint.

 

[Scaaty]

Re: Sandblaster Media

Try any quality Auto Paint shop supply...big 40lb bag only $20 around here

 

[bucky7680]

Re: Sandblaster Media

I agree with 12FOOTER, Unless it is a professional qaulity sand blaster and compressor (not a siphon feed) you are better off using an angle grinder with a wire brush on it. Then use the sand blaster to get to the places that you weren't able to get. The sand will get every where, plan on repacking the wheel bearings. Make sure to use several layers of good duct tape to protect the areas that can be damaged by the sand. Out here Lowes has silica sand which is the most economical to use. Don't use anything coarser than #20. Did I mention that the sand will go EVERYWHERE? Make sure the respirator is the best you can get. Don't even think of using a paper one and use a blast hood if you can.

 

[burroak]

Re: Sandblaster Media

Just to give you my experience with blasting trailers; a blast shop will charge you $250 - $400, but it will be clean, very clean.

As DYI project, anything less that a tag along compressor and a 100# pressure pot will be an exercise in frustration and futility. In my area, the compressor goes for $40 for 4 hrs, the pressure pot goes for $80 per day and the blast media will be approximately $6 per 50# bag and you will need 10 bags to do the job. Line up some other items to clean up if you have any media left over.

If the project is not a beauty contestant, a good stiff wire brushing (rotary or manual) and the application of a rust encapsulater will give you a good enough base to to apply a industrial enamel with a gun or brush. Actually the brush will deliver more product to the nooks and crannies of the frame than a gun will - that's where the paint job will fail first if you spray the trailer. Brushing will allow you to control runs better than spraying. Once the trailer has been coated with color, the money sides of the trailer can be smoothed and sprayed for a better cosmetic look. The cost for the low end job should be less that $20 for wheels and brushes, $20 for the rusticide/encapsulater, and $30-$40 for a gallon of enamel, brushes, and rollers.