seal seems in metal plenum

Karl, would continuous welds be sufficient? It does not seem as though you have a shortage of welding electrodes. :)

"Karl Townsend" wrote in message news:3OwVf.7047$ snipped-for-privacy@newsread1.news.pas.earthlink.net...

There's a product that's like foil duct tape, check a heating/cooling supply house. Here's a couple of links. This stuff is great!

There is a liquid duct sealant, some sort of flexible-rubbery stuff. Don't know how paintable it is.

Then there's household caulk, which can be had in known to be paintable formulations.

"Karl Townsend" wrote in message news:3OwVf.7047$ snipped-for-privacy@newsread1.news.pas.earthlink.net...

Sounds like a good use for Automotive seam sealer...Paint on or in a caulk tube.

HTH

Jeff

"Karl Townsend" wrote in message news:3OwVf.7047$ snipped-for-privacy@newsread1.news.pas.earthlink.net...

What more would you want??

...

Thanks, this is what I'll use.

Karl

Beside taking forever to do it, the welds will warp the sheet metal.

FWIW, I mig this. The electrodes I have are only good for thicker metal.

Karl

I have used the heavy foil tape enough that I would not use it in a vibration area.

I would look to acrylic or silicone caulk for something like this. More likely acrylic, given the paint requirement, though you could use paint that is color matched to the silicone, like white.

Cheers Trevor Jones

Strawberries? What happened to the apples? ;-) I go through Oxnard regularly, right past the pro pesticide places (AgRX for one) that own these blast sprayers. And they're put together to be rugged.

More weld. Seriously - go back and fill in all the blank spots between the stitch welds, an inch at a time so it doesn't warp on you. Then get out the angle grinder for the pre-paint clean up.

If this blast sprayer is to be mounted on a tractor and bounced around regularly by hired farm workers who don't care about being gentle on the equipment (they just want to get done and go home) you have to build it bulletproof or it will crack and fall apart. And they won't say anything about it when the crack appears, only when it fails totally.

(And they get the afternoon off while you fix it.)

Put X bracing anywhere it might twist, brace all the register opening arms, triangulate the arms mounting it to the tractor three-point and the fan unit. Stiffen any large flat metal areas so they don't "oilcan" on you. Then go drive it around and have someone watch and videotape while you hit bumps - you may be able to see where it needs more reinforcement before breaking it.

After that, you can get spot putty and urethane based seam sealer/filler (to make your welds look good) from an auto parts with an auto paint department, use stuff that is meant to be painted. They'll also have the 'tractor paint' for the finish coat.

And you might want to paint the inside so it doesn't rust as fast.

-->--

How'd you know about my employees?

Lots of good advice in your post, Thanks for taking the time.

Karl

"Karl Townsend" wrote in message news:3OwVf.7047$ snipped-for-privacy@newsread1.news.pas.earthlink.net...

When we built large air handlers for a convention center, we simply sent one of our 'rats' (a young guy) down inside the duct with several boxes of Butyl caulk and a air powered caulking gun. The stuff takes a couple of days to set up strong, but it will withstand 8-10 psi across a 1/4" gap, Never EVER loses its flexibility (out of sunlight), and sticks to ANYTHING.

LLoyd