[Coldman]

I don't do a lot of 7016/7018 stick welding these days, certainly not enough to justify the cost of a hot box. Been keeping my eye out for suitable leftovers and finally got this long term storage idea together that I've had for a while.

lohy.jpg (77.83 KiB) Viewed 920 times

It's 2-1/2" copper tube, end cap and screwed fittings to seal. Soldered in a refrigeration service valve. The tube will hold a full pack of rods, seal it up, run the vacuum pump and back fill with dry nitrogen. Done.

I can do all these things, being a fridgie, I already have the gear. It's good to be a fridgie.

[MosquitoMoto]

Well done Coldie.

I think that every Coldie appreciates that it's good to be a fridgie! Great use of your skills to create something that you'll be using for many years I'm sure.


Kym

[Coldman]

Actually you don't need a vac pump. You could put any ball valve on each end and purge nitrogen or argon through to displace air then shut valves. Does the same thing.
That way cheap pvc materials could be used.

[Coldman]

I wonder if a deep vacuum would recondition lo hy rods the same way that oven baking does. Anyone know?
Maybe a rod manufacturer would have to answer this.

[Poland308]

I don't see why it wouldn't work. Same principal you just changing the pressure and useing ambient heat to vaporize the water. I used my vac pump to dry out a cell phone once. Used a steel plate with a fitting taped into it and used an old piece of inertube for a gasket and a glass jar for the vac chamber.

[Coldman]

Update. 2.5" copper stores about two thirds of a packet.

[MinnesotaDave]

I wonder if a deep vacuum would recondition lo hy rods the same way that oven baking does. Anyone know?
Maybe a rod manufacturer would have to answer this.

It does not work - I wondered the same a few years ago.

What I found is that the flux is hygroscopic and the water from the air chemically bonds to the flux.

It takes energy to break this bond. That's why the re-bake temp is so high.

A rod oven's temp is high enough to ensue there is no moisture in the box to be picked up by the flux during storage.

The welding arc will break the bonds of course, and split the water into hydrogen and oxygen.

This is how the hydrogen is transferred to the weld.

[Coldman]

Thanks for that. Makes sense. I sent a request for info to cigweld but no answer yet. Shouldn't have bothered and gone straight to the top.