10 replies to this topic

[Petrol]

The door skins on our MPI Mini have welds where the lip on the door skin meets the door frame (Circled in red)



Welding these areas will burn off any protection applied to both the prepared door frame and the inner lip of the new skin. I am thinking of using Sikaflex to bond the skin on. The plan is to apply a bead to the door frame, drop the skin on and bend the lip of the door skin over. It seems like a good idea in practice but are there any downfalls? Just to add, I am planning on welding the top of the new skin to the window surround and where it wraps around the top of the door, above the check strap. Also the area at the back of the door, above the catch.
I am trying to avoid welding at the bottom of the door where rust protection is of course, important.

Anyone any thoughts?

Pete

[mini-luke]

You wouldn't be the first do do it and lets face it it's not going to fall off! I don't think they had spot welds where yours are as standard anyway, looks like a MIG weld which would suggest it's been re-skinned and someone has added some extra tacks

[sonikk4]

Are you stripping the old skin off. The rust you see in your pictures will be in between the skin and the door and will need to be sorted out.

Normally the skin is spot welded on in a couple of places along the bottom and sides then seam welded at the top sections. Then there will be a spot weld where the window frame exits above the skin.

If you use weld thru primer then you will have protection there. Again once finshed you can apply a small bead of sealant along the edge and on the inside spray Dintrol or Waxoyl to protect it.

There have been arguements on here about bonding metal panels onto a mini. For me if its been welded on by the manufacturer it should be again buts thats just my personal thoughts on this. However if it was a Aluminium skin then thats a different kettle of fish.

[Tupers]

My main concern would be with the setting time of the Sikaflex. If it goes off before you've had time to hammer to dolly the skin tight then you could end up having to remove the skin and start again.

Personally I would clean the door frame up, make any repairs necessary and then paint the frame and skin with Zinc 182 primer before fitting the skin. The Zinc 182 wont burn off like regular primers and will provide good rust protection especially if you also wax oil the inside of the door.

[Petrol]

The car is unmolested and original so the welding is as Rover built it. I appreciate where you are coming from sonik but weld throu has it's limitations... as soon as you weld - it's gone. As for the setting time of the sikaflex, very good point!
I have one door in bits and one intact... just to compare

[minidaves]

that aint how rover did door skins end off

[M30]

I served my time rebuilding Land Rovers which as you will know have Aluminium skins on steel frames. We had no option but to use seam sealer and then peen over the skin.
I would suggest that rover tacked or spot welded the skins on to hold them in the right position until the skin was peened over, rather than to hold it on afterwards. I wouldn't worry about the sikaflex going off that quickly.
Just a tip. When we did the Range Rover skins (which were a slightly curved door like the Mini) we would place a decent thickness clean plywood board on the floor, and then place the door face down on it. Knock over a small piece in each bottom corner to hold the skin in the correct position. Then you need a kind helper to get hold of the top of the window frame and raise and lower the door whilst you knock over the skin that is in contact with the board, working from one end to the other. You'll get a much better result than using a dolly. Dont try and knock it right over in one go it will take 2 or 3 passes along the full length of each side.

Stu

[skoughi]

When I reskinned my doors I cleaned off the transport primer on the inside then etch primed then a couple coats of hammerite primer (only because thats what I had primer wise at the time), fitted the door frames on the car and got the window frames as central as poss in the door opening then held the skin on the frame until it was central in the opening and made a scribe mark on the window frames where the top of the skin was. Removed the door frame and laid the skin on a folded up blanket. Then I applied a bead of adhesive along the edge of the skin where the door frame sits then laid the frame onto the skin and lined up the scribe mark, then applied another bead on the edge of the door frame and then started bending over the skin edge with hammer and dolly until it was halfway bent over, took about 2-3 passes. Finished it with a large pair of vice grips and and an off cut of 10mm ply on the skin face to protect it. Bent the edge flat in about 3-4 passes with the grips and cleaned off the adhesive that had squirted out. Welded the top of the skin where it meets the frame, job done. Hardly any marks on the outside of the skin to speak of and a good bead of adhesive on the inside on top of a good coat of primer. Very happy with it, until I dropped one yesterday and put a little dent on one edge!

[tiger99]

Obviously you can't adhesive bond structural joints in the shell which were designed to be welded, not can you replicate the conditions at home which manufacturers use to bond certain parts of modern cars. But door skins are the perfect place to use adhesive bonding. I am not sure that Sikaflex is the most appropriate material here, but if you google for automotive structural adhesive you will find lots of interesting products, some of which also have weld-through properties, and if combined with the normal amount of spot welds could be used in various places, for extra strength or waterproofing.

I can see considerable advantage in having the lower edge of the seam completely filled with adhesive. It will be stronger than a simple folded over edge, there will be no fretting between the surfaces, and no ingress of water.

[skoughi]

I agree with what you say about sikaflex. I used a type of sikaflex on a bit of my shell and found it had hardly any adhesive qualities at all, although in its defence I did scran it from work and I think it may have been out of date! Also there are different types and one may work better than others, the air temp will probably make a difference too. I used sumo grip on my skins and it seems to be doing its job. Squashing down the skin edge with large jawed vice grips seemed to help as well as the grips applied the same force with every squash so I was able to not squeeze the parts completly together thus leaving a very small gap that is now filled completly with adhesive/sealer.

[The Principal]

Another option try these guys heard good things about them - http://www.minidoor.co.uk/