Walnut Shells...how many bags?

[alaskabearhawk]

I'm going to be cleaning metal parts soon and going to pick up some walnut shells for blast media. Kinda scarce here in Alaska, but just wondering about how many bags would it take to clean the fuselage and related components. I reserved three 50lb bags of 12/20 at a supply house in Los Anchorage and just want it to be enough so I don't have to make the trip again. Any input would be appreciated.

[spinningwrench]

If your doing small parts in a blast booth, glass beads also work very well and might be more available.

[alaskabearhawk]

Yeah, I have a pretty large glass bead cabinet...but the fuselage just won’t fit! The big parts also fit, but just because it fits doesn’t mean I can get the gun in each spot, especially the ends.

[svyolo]

Blasting and priming a whole fuselage is one of the reasons I bought a kit. I figured I could get good enough welding. I am good enough painting. How much real estate do I need to blast/prime/paint a fuselage. It seems like if I can sandblast a fuselage, I might as well put a shingle out and open a sandblasting business.

[Ed Welfred]

My situation may be different than yours but I used four 50 lb bags of sand. I tried some other abrasives but not walnuts. I picked up a 'garage in a box' that was 10 ft. x 20 ft. and put a tarp on the ground so I could catch and reuse the abrasive. I only blasted the weldments and used emery cloth strips to clean the tubing. Southern Ontario is not considered to be particularly humid but I was finding flash rusting so I cleaned one section at a time and primed and top coated before doing the next section.
Ed

[alaskabearhawk]

Thanks. I really want to avoid sand because of the health issues involved. I have a set of aircraft floats that I need to clean too, so maybe I’ll just get a few extra bags and if I have extra I’ll use them on the floats.

[rodsmith]

I'm not sure walnut shells would clean the steel well enough. Must be a lot more expensive than sand. I used 8 50# bags of very fine sand outside, was not trying to catch and reuse it, had the fuselage on a rotisserie or never would have been able to get all of it. So easy to miss spots. I remember a picture of Bob standing his fuselage on end to blast it.

[alaskabearhawk]

I really want to avoid the dangers of silica sand dust and inhaling the stuff.

[BTAZ]

I used a coal slag based abrasive like this (Black Diamond Medium Blasting Abrasive)
https://www.tractorsupply.com/tsc/product/black-diamond-medium-blasting-abrasives

Worked great and not as much a safety issue .

[davzLSA]

I hired a professional sand blaster and he used the coal slag, It did a great job of cleaning the metal and left no residue. It cost me $500 but by the time I tooled up and bought the blast material and spent the time it would have cost me much more than that, I think I got a real bargain. It took him about 2 hours to do the whole fuse and all the loose parts. You might consider this route, it saved me lots of time and money.

[spinningwrench]

If you use a commercial sandblaster you need to be real careful they don’t hit it with the full force they normally use as it can really warp tubing. Ask them to dial back a bit.

[davzLSA]

The guy I hired did dial his blaster back, he knew he would shred my tubing if he didn't.

[Chewie]

A harbor freight gun and a harbor freight box of walnut didn't do $#!+ to clean my weldments. Thinking something more abrasive.

[alaskabearhawk]

Good to know...

[Ed Welfred]

TSC stores advertise their abrasive sand as non silica. If that helps.
Ed

[alaskabearhawk]

Being in Alaska, we have no free shipping, no TSC or HF stores.

[Mark Goldberg]

For those of you yet to sand blast and reading these posts - it might be good to understand that some blast media sold is too aggressive. At the kit factory we bought a small sand blast cabinet. With it came some bags of glass bead. We tried it on some scrap and then looked at the material under a 10X magnifying glass. The surface of the material was damaged, and we threw away that blast media. So use caution what material you select and examine closely the effect it has on your BH parts. Mark

[Russellmn]

Did you play around with pressures? Sometimes aggressive media can work really good at low pressures and not damage the base metal... I plan to have my fuse powdercoated when it's done, will have to do some experimenting with my coater to make sure it's done right.

[Chewie]

So, if it's not proprietary, what media did you go with?

[Mark Goldberg]

We just use silica sand. The nasty stuff. The worker has a full BIG helmet with fresh air supplied. Mark