welding pipe to flats

[Henrik]

So I was dabbling with welding some metal pipe (2mm mild steel wall) onto a flat base, like so:

I'm more concerned with it being leak proof at present, rather than being structurally strong, however what are the best ways to achieve this with MIG?

Whilst welding this, I ground back the "starts" of the welds, as I'm guessing adhesion/fusion will not be as strong there as further into the weld when things have heated up, and then covered them again (starting a bit further away, obviously).

Always looking to learn new things, so are there any other dos and don'ts?

I have a slight bit of undercut on the plate, but it doesn't really worry me, as it's not a structural item. I'm guessing taking the amps down a notch and/or turning down the wire speed would fix this.

The above was done using my clarke 135te welder.


Some more weld pics and the half way finished article (modified from a previous incarnation):

 

[Justme]

To make the job easier I would mount it on a turn table. You can then do it all in one long smooth weld. Stopping & starting is a sure fire way of getting micro leaks if you not 100% in your welds.

What sort of pressure will this be taking?

 

[Henrik]

About 2-3 psi tops. It's to hold some petrol, basically.

If it leaks, I might try to solder the joints, as I'm guessing that might draw solder into any pin holes.

 

[Dave Richards]

No disrespect Henrik, that looks really poor. to reduce the risk of leaks you need to reduce the number of start stops. You should try to go around this in two or maybe three. The turntable idea is great if you have one, even then go for two rather than one pass as you can top and tail start/ finish.

 

[Henrik]

Hmm, it was done in four goes. Not sure why the weld came out looking so wavy on the pics (probably because I wasn't moving the torch smoothly).

and no offence taken, I'm here to learn after all

 

[Henrik]

Well, filled it up with petrol today, and it's not leaking, so happy days

 

[andeep]

I would pressure test it just to make sure

 

[Lawnmowerboy]

Petrol isn't the best way to check for leaks. Yes it creeps a lot but what if it did leak. Theres not an easy way to purge it properly.

 

[Henrik]

That is a good point. What do normal people use?

 

[lshigham]

Things that are not flammable! Personally, I'd plug all the holes and pressure test with water, I've got a proper pump but you could use the mains depending on pressure desired

 

[super noob]

Why do you need a swirl pot on a low pressure system out of question ?

 

[Henrik]

Why do you need a swirl pot on a low pressure system out of question ?

Cornering hard (on track) with less than about half full fuel tank results in an uncovered fuel pickup == engine cuts out.

The pot will be filled by the in tank pump, and the tank will feed the second pump - the pot will give about 1 litre of extra capacity, which should be enough even for the longest corners in the uk