Plug welds

[Rivertest]

Hi all,

Been a member for a while and been keeping my head down, but nows the time to get stuck in. Clarke 160TM arrives tomorrow, supplied by weldequip.

Can someone confirm that when using plug welds with 2 differing thicknesses of metal, in this case an inner sill and outer sill, the 7.5mm hole should be on the thinner steel? Also I assume that the power setting should be set for the thicker sheet. I can use the gash metal I've taken off to test with but just wanted to know the sp to save some testing time.

Picture attached to give you guys a flavour of what I'm up to.

 

[danelectro]

Got to say I'm a little bit worried, there doesn't seem to be much holding that baby together apart from a bit of 4x2 and some axle stands.
I'd hate to see your project looking like a banana.

What car is it ??

Edit: Sorry that sounded really negative, was a bit shocked that's all!!!

Well ideally I'd go through thin to thick, and settings to match the thick, but to be honest variations are not that bad on bodywork, it's not like trying to weld a bit of 22 guage to 1/4 plate!! as for settings, well go for the thickest setting I guess, but trial and error is your best bet.

And before you weld it all up, make sure the door fits the hole!!!!

You're doing a good job, very clean prep I have to say. but I would've prefered to see it all braced up before you cut things out!!!

 

[Rivertest]

What car

Thanks Dan, I thought as much.

Its an MG Midget believe it or not. I've done a bit of reading up and its braced as per recommendations.
As for the door, I've just taken it off and will definitely be putting back on before welding up. As per the experience of other restorers it sags very slightly in the middle if you don't have the jack.The car as a whole is pretty rot free structurally but I had a very bad 'off' back in 1987..!!! , which totaled most of the near side. I've finally got a bit of time on my hands to sort it.

Forgot to say, the car is also levelled on the stands.

 

[KTMMICK]

Thanks Dan, I thought as much.

Its an MG Midget believe it or not. I've done a bit of reading up and its braced as per recommendations.
As for the door, I've just taken it off and will definitely be putting back on before welding up. As per the experience of other restorers it sags very slightly in the middle if you don't have the jack.The car as a whole is pretty rot free structurally but I had a very bad 'off' back in 1987..!!! , which totaled most of the near side. I've finally got a bit of time on my hands to sort it.

Forgot to say, the car is also levelled on the stands.

It'll be fine like that, done a few sills on MGB's in exactly the same way. As you already mentioned you just check the doors fit. Sure it'll be ok though! If you are using pattern sills though be careful as they give you a false lineup. If you know what I am saying.........the edges are not always correct. Just my experience.

 

[Rivertest]

Yeah I know what you mean, I bought all the panels a few years back, most of them were heritage panels but the inner sill is a re pro and funnily enough it was slightly to long at the front when I offered it up. On closer inspection I found that the bend at the footwell end had been done slightly in the wrong place. Sorted that one ok.

Soooo, you may be able to answer another question for me KTM. By the looks of it the inner and outer sills were originally through spot welded, so they were fboth fixed to the tub at the same time, I assume after a quick spot weld to hold it all in place. I'm in 2 minds to hire a spot welder and do the same, making sure that everything lines up nicely, or, use plug welds and do them separately, which will of course take a bit longer, what do you think?

 

[badersbus]

Hi Rivertest.
Nice project you have got going on. With regard to the sill / inner sill floor pan joint. In the past i have done it several ways.
1 Spot weld the entire lot together , but you have the expense of hiring the gear.
2 Mig plug the inner sill to the floor pan first , grind the weld nuggets flat and then mig plug the outer sill to the inner sill flange.
3 Drill holes through the inner and outer sill at the same time and then mig plug the two outer panels to the floor pan.
Dont forget to use weld through primer on any mating surfaces.
KTM is probably right , but i would do what Danelectro says as well on the bracing. If you have not got a Aperture brace , just a piece of angle iron would also help , tacked in between the A post and the B post. Try to put it in a position where you can still hang the door though.
Looks like you got it sorted though
Good Work
Kirk.
PS sorry for jumping in

 

[Rivertest]

No worries Kirk, thanks for the advice especially regards the weld through primer, it was gonna be my next question to the forum. Can you tell me whats the best and cheapest primer and where to get it from?

 

[Blurk99]

i'm not sure about the cost, but U-Pol do decent weld through primer - should be available in your local halfords - i think it's 'number 2' for zinc rich primer, green and silver rattle can

Jim

 

[Rivertest]

Ok Thanks Jim

 

[badersbus]

i'm not sure about the cost, but U-Pol do decent weld through primer - should be available in your local halfords - i think it's 'number 2' for zinc rich primer, green and silver rattle can

Jim

Thats the one