9 replies to this topic

[mk=john]

Hi
I am currently restoring my 1990 Mini, and have replaced the left hand door step area. Anyway it is all welded in, and I have plug welded (with my MIG welder) the door step flange to the sill flange. I have made the spacings about 25 to 30mm.

I know that in the factory, that this area was roller welded, and this also had the effect of keeping water out.

I have now completed all the plug welds, and linished them smooth on the flange. What is the best method of keeping this flange joint watertight, so water does not enter between the welds? Is seam sealer applied to the outside going to be OK. I just wander what anyone else has done when repairing this area. Also, ids my technique for plug welding the sill flange to the bodyseide flange OK for an MOT?

Photos attached

Thanks

[rosco454]

It should pass an mot as it was spotwelded from the factory.

As for making it watertight,spray your chosen sealant (waxoil etc) from the inside of the sill through the vents using a thin tube.Direct it as best you can into the back of the seams.
For the outside if you want a neat finish its a bit more awkward as seam sealer isnt the neatest of stuff.I would rub waxoil on a cloth into the join in the seam and then clean back the excess.There may be a better way to do this but its the way i do mine.

[jack_marshall]

If I want to make something like that join water tight, I use seam sealer.

Just keep rubbing it into the gap, applying more and removing as needed until its all sealed up!

Before you do that though, go along the flange with a flat face panel hammer and a flat dolly to get the join as sealed and straight as you can!

Looking good as usual mate.

[mk=john]

Hi Guys

Thanks for the help. I was a bit worried that the plug welding is not acceptable for an MOT. I know the original sill flanges were roller welded, which effectively puts the spot welds next to each other. Any advice on that, eg, would I have to seam weld the entire length of the flange including the rear arch flange-bodyside flange? This would put lots of heat into the panels which I want to avoid. Its already plug welded at 25mm pitch.

But, I will be using waxoil or Dinitrol for inside the seam joint, and may decide then on seam sealer or waxoil for the outside of the flange.


John

[rosco454]

I always thought that only the roof seams were roller welded to keep the joint watertight?

I may be wrong though,if so just tell me to shut up lol.

[panelbeaterpeter]

Close spot welds are perfectly acceptable, and will pass an MOT. It is very important that you use a weld thru primer on both faces before clamping and welding, and make sure there is no gap between the panels when you spot weld it. If there is a gap that is too big for primer to flow into, apply a bit of wet on wet PU seam sealant after primer and before painting. If you do that and waxoyl inside the sill you'll be fine.

[mk=john]

Close spot welds are perfectly acceptable, and will pass an MOT. It is very important that you use a weld thru primer on both faces before clamping and welding, and make sure there is no gap between the panels when you spot weld it. If there is a gap that is too big for primer to flow into, apply a bit of wet on wet PU seam sealant after primer and before painting. If you do that and waxoyl inside the sill you'll be fine.

Hi peter
Thanks for that. I have used U-POL Weld through Zince primer (green and grey aerosol can). The plug weld spacings are about 25 to 30mm apart, so I hope thats OK. I have done plug welds with my MIG welder, as I do not pocess a spot welder. Bye the way, even though I am being meticulous with this car, how does an MOT inspector verify the welding when everything is assembled and painted? I have taken lots of photos during the restoration to include all of the welding carried out so far. I want this to be a concours car!

Cheers
John

Edited by mk=john, 05 April 2009 - 10:41 PM.

[Ethel]

A tester can't do anything more than look. Your welds sound adequately spaced, they weren't seam welded originally. If you think about it a seam weld would isolate all the seam to the outside of the join and create a nice straight "fold" line on the inside & would actually be weaker. The join length around a spot weld is pi x the diameter so spot welds with gaps twice the size of the spot will have just as much steel joined as a seam weld.

[jack_marshall]

Dont go near it with waxoyl or dinitrol before painting the car!

[rosco454]

Sorry, i wasnt very clear on my first post.

The method ive used in the past is the one in my first post but after paint.
I have never put seam sealer in the join beforehand though - should i be doing this?

Edited by rosco454, 06 April 2009 - 06:42 PM.