Waxoyl and welding

[zaph]

The ends of the sills on my dolomite need welding, but the sills are full of some rust proofing. I'm told this can be flammable, and welding would be a bad idea.

How do I deal with this stuff in a box section before welding? How do I remove it, and how much do I need rid of to be safe?

 

[the snooper]

most underbody protection is flamable, you would have to cut away the damaged area then probably clean back 2 or 3 inch before welding it.
just keep some form of extinguisher with you, it doesnt burn like petrol

 

[SiPMerlin150]

I will melt and most likely run out of any nearby holes, burn you and possibly will ignite. Take all precautions and have a water bottle to squirt on the fire or better, have a powder fire extinguisher on the ready. If you can reach it, scrape it out using a razor blade. If not, only weld in small sticking to small stitch welds, keeping the heat down.

 

[super noob]

Waxoyl burns but can be put out easily enough with a pat from your glove or a blow, I welded my landy up and it was coated in the stuff

 

[zaph]

most underbody protection is flamable, you would have to cut away the damaged area then probably clean back 2 or 3 inch before welding it.
just keep some form of extinguisher with you, it doesnt burn like petrol

Oh I had visions of the tower inferno. Ignite one end of the box section and the flame shoots along it.

 

[the snooper]

no nothing like that, you usually blow it out

 

[SiPMerlin150]

Last week I put a full new outer sill on my fiesta, not before completely (maybe stupidly at the time) loading up the inner sill with antistonechip/water proof anti corrosion gear and spraying a few liberal coats onto the inside half of the new sill. I cleaned off the areas around the plug weld sites of this paint and carefully welded it into position. Had a smoke show which scared me a little, but slow progressive welds in various places kept the whole thing from burning down. I trust that the new sill shouldn't rust ever now!

 

[the snooper]

i hope you re coated the inside afterwards as the weld areas will be exposed and the heat will have damaged the coating

 

[SiPMerlin150]

i hope you re coated the inside afterwards as the weld areas will be exposed and the heat will have damaged the coating

Suppose you could say the same with weld thru zinc primer? Yes, there was a nice straw attachment that was inserted into the sill drainage holes and sprayed inside. Hopefully that will cover that. The panels were factory primed with the typical matt black paint. This stuff seems rather good at coping with nearby heat from welding.. It will be on there for sometime before that thing rusts through, i'm sure.

 

[jordan1]

I think the old Finnegans Waxoyl was spirit based, so well flammable, I presume the current one will be similar. Take care.

 

[ben8vgte]

I replaced the cills on my old Astra then waxoyled inside, then a few weeks later fitted a cage..


Fresh waxoyl is very flamable! Cue the hose and a repaint of the cill and that was from splatter running down the inside of the A pillar from the top.

If you think you might need to do some more welding soon then leave the waxoyl recoating till you are sure it's all done. Old waxoyl is not as bad really.

 

[sardine]

insignificant fire risk

i waxoiled a peice of plate as thick as i could get it, and welded the backside of it with a 3.2, the next day, to simulate welding a boat hull, there was just a small local flame which did not carry on when i stopped welding.

some people were saying not to wax the bilges of steel narrow boats in case you needed welding at a later date, i proved it was not true i think.

I don't know about sills injected full of the stuff though.

 

[ibrooks]

Older stuff will have had time for the more volatile parts to have evaporated and what's left really is like wax. It will burn but not at a huge rate so the fire extinguishing stuff you'll have around anyway to deal with minor flames will cope quite happily.

For box sections...... I have an out-of-date CO2 extinguisher that I keep around for stuff like this and when welding I periodically blast some CO2 into the box section. Depending on holes in the box I might duct tape over them so it doesn't just flow straight back out - depends on the circumstances really.

One thing I would say - once you have finished welding stick around for a while and check that the area has cooled down and isn't staying warm. It's easy for a small flame to be smouldering away inside a box section and for it to develop into a full blown fire when you have gone away.

Iain

 

[steveo3002]

yeah good advise there..never finish up welding and walk away for the night , check back on it while you clear up etc and feel around if anywhere is hot

always worth having a hose handy , smaller flames will go out if you half trigger the gas out near it

 

[norsa]

Something I learned many years ago is you must consider when heated with a welder, it turns to liquid and as such, this boiling oil will run out of places other than the immediate weld areas. You won't know about it untill it soaks through your clothing!! I still bear the scars.
Nick.

 

[PhillipM]

I usually turn the wire feed off and purge the sill full of CO2/Argon first if I have to weld near fresh cavity wax.