Mig Welding near a plastic diesel fuel tank

[rumpelstiltskin]

Ok,needing to do a little mig welding to the rear chassis rail on my rover 75 diesel.Trouble is it's really near the fuel filler neck.Can i just wrap the filler neck with a damp cloth and maybe use a piece of sheet metal as a shield?There are no fuel leaks near where i'll be working.

[JulesB]

Sorry I can't offer any advice as I have no experience with welding, but this sounds like a recipe for disaster!

[Squiggs]

I'm no expert but I know hot will melt plastic and that petrol fumes ignite very very very easily.
So even if there are no fumes there now you've only got to burn a pin prick of a hole to let the fumes out.

[rumpelstiltskin]

Its a diesel!If i was welding near a petrol tank (like ive just been with my renault 5 turbo)i didn't hesitate to take reserve tank i was near off.I was just wondering if diesel has to be treated with as much respect?I know even petrol fumes can be set alight but with diesel i just wondered if general shielding would suffice?

[Squiggs]

I wouldn't take the chance anywhere near a flammable liquid.
And to be quite honest I don't think anybody is going tell you it's going to be safe and that you won't blow yourself up - and if they did - what if you went ahead and they were wrong?
Your own common sense must tell you that the only truly safe answer that you could rely on would be given by an HSE officer .... and I've got a sneaky feeling they wouldn't be saying 'yer carry on you'll be fine'.

[HustleRussell]

Depends on how close we're talking but if you're confident you can protect the filler neck adequately, then I'd say proceed with caution. The biggest risk is a bit of splatter getting onto the plastic filler neck and burning a hole in it. Diesel is less volatile than Petrol but can in certain conditions form a simular flammable vapour. Another consideration would be keeping temperature in the area as low as possible, so using several stitches with cooling time in between.