Surface prep... sandblast vs. grind?

[dragoneggs]

I haven't done proper research but curious as to which is a better surface prep process for welding? Is bright metal (grinder) better than grit blasted and solvent wiped? Talking mild steel here.

 

[Tractor Seabee]

In the time it takes to set up to sandblast and then clean up the grinder will have it done. In pipe welding we never cleaned the surface much unless it was painted. light rust is usually not a problem, just wire brush it. Most pipe comes with a light varnish finished that was all burned off by the time we got to the last pass. We even ignored some primers unless lead or zinc bearing; because you don't want the fumes. TIG, a different story, needs to be bright clean. Certified welding (double on Xray quality) you want things clean, and grind every pass, especially the corners. I keep three 4.5" angle grinders ready to go; wire brush wheel, 1/4" grinding wheel, and thin cut off wheel. Do you sand blasting when ready to paint.

Ron

 

[TMGT]

Depends on what I'm doing but prefer blasting if practical as it usually provides a cleaner base, plus I really hate grinding honestly.
Bright metal or blasted finish doesn't matter as long as its clean.

 

[dragoneggs]

I'm set up so I can actually sandblast about as fast as I can grind but I think you are right! Grind locally and blast when ready to paint.

Just curious though if there is a weld performance difference depending on the prep? I have a HF modified cabinet with Tacoma Company products and am really enjoying it. Set up a slick suction/filtration system that makes my blast cabinet 'rock'. I just restored a pre WWII Rock Island vice and been blasting a few other small projects. My latest project is a couple of trencher attachments that will be made with scrap from cutting down my back blade to proper size for my BX. Another thread hopefully.

I do about the same with grinders... all HF cheapo's. Flap disk and two hard wheels, thin and thick. Need a fourth HF grinder for the wire wheel.

 

[dragoneggs]

Depends on what I'm doing but prefer blasting if practical as it usually provides a cleaner base, plus I really hate grinding honestly.
Bright metal or blasted finish doesn't matter as long as its clean.

Thanks TMGT... I am enjoying popping in small pieces to blast rather than grind. Not a big grinding fan either.

 

[TMGT]

Would be interested in your blast cabinet setup, I have a HF cabinet that I've never used, hope to get it online once I get the new shop built but I know it'll need some help.
Trying to figure out a cost effective dust evac system.

 

[dragoneggs]

Would be interested in your blast cabinet setup, I have a HF cabinet that I've never used, hope to get it online once I get the new shop built but I know it'll need some help.
Trying to figure out a cost effective dust evac system.

Here is a pic of my setup. Lots of mods to the HF cabinet thanks to Tacoma Company. But overall idea is portable and transferrable dust collection. The dust deputy mounted on a sealed bin above my shop vac. Welded up a light weight support frame and all on casters. Basically a pre filter before my vac. Probably worth a separate thread if folks interested but I can move this between tools. Blast cabinet, miter saw, router table, etc. I also have a dust collector (in the background) that is soft plumbed to my table saw and jointer, and with a bit of finesse, my wood planer.

 

[TMGT]

I'm not sure the pic worked.

 

[dragoneggs]

I'm not sure the pic worked.

oops!



It is a sweet setup.

 

[TMGT]

Interesting setup, I'll have to look into that. I've had the cabinet for almost 6 years I think and never used it