Will it crack?

rmattila · Post by **rmattila** » Tue May 31, 2011 10:30 am

MOT on next Friday, no time to change the windshield before that. But the A pillar must be welded anyhow.

What do you say, any change of patching the thing without cracking the windshield in the process?

Post by **Defender110** » Tue May 31, 2011 1:05 pm

The windscreen won't crack if your using mig but the seal will set on fire

unless you can squease in a piece of plate as a deflector without welding that too.

citronut · Post by **citronut** » Tue May 31, 2011 1:17 pm

so how are you going to weld along side the screen with it still in place,

regards malcolm

rmattila · Post by **rmattila** » Tue May 31, 2011 1:25 pm

I'm thinking of welding the windshield side first, from inside the box, and then bend the patch down and continue from the outside. I'll try to put a couple of steel sheets in between in order to prevent the glue and glass from getting damaged

Gibbo2286 · Post by **Gibbo2286** » Tue May 31, 2011 1:54 pm

There is a heat shield foam that you can spread along beside where you intend to weld that stops the heat spreading too far. can't think what it's called offhand. Another idea I've seen it to use 'drywall mud' instead. Gibbo.

RxBX · Post by **RxBX** » Tue May 31, 2011 2:26 pm

rmattila wrote:I'm thinking of welding the windshield side first, from inside the box, and then bend the patch down and continue from the outside. I'll try to put a couple of steel sheets in between in order to prevent the glue and glass from getting damaged

I thought that exactly as you've stated or alternatively the only other way would be to mig/stitch a 90 degree bent/plate section so as you've got enough access to weld onto the inner window section, then make up another section to weld/cap by over-lapping on the mid/outer portion (of the new piece you've just welded in) on to the 'A' pillar then stitch/weld the length on the outer pillar just near to where the door shuts up to (If that all make sense ?) !

But as already stated take care not to over heat the area adjacent to the window so not to get excess heat into to the glass or possible weld spatter burning into the glass, also take care not to burn/scorch the rubber drain pipe that can be seen near to where your going to weld.

But I think it's probably best to go along with the first method IMHO !

Best of luck with the repair and MOT !

citronut · Post by **citronut** » Tue May 31, 2011 7:31 pm

i dont hold up much hope as the heat will travle in all directions, so the tin the screen is sitting against will get very hot, and im sure it will do the screen a lot of no good,

regards malcolm

sdelasal · Post by **sdelasal** » Tue May 31, 2011 7:47 pm

how did you cut out that section ? looks very neat. Steve

rmattila · Post by **rmattila** » Tue May 31, 2011 8:45 pm

The glass seemed to survive:

http://www.rmattila.com/images/remontit ... lar_patch/

Not a showpiece, but it'll do for a few more years.

RxBX · Post by **RxBX** » Tue May 31, 2011 9:59 pm

Well done, looks a decent job compared to how it looked before !

I like the air powered jig-saw

Wooscary · Post by **Wooscary** » Tue May 31, 2011 10:58 pm

In your hands anything is possible it would appear!

Mothman · Post by **Mothman** » Wed Jun 01, 2011 5:00 am

Wow,

i would not have believed it possible without the removal of the windscreen. Well done once again.

Andy

electrokid · Post by **electrokid** » Wed Jun 01, 2011 9:47 am

Excellent job Sir

The nearest tools I have that would come close to tackling the cut-out are a Dremel (which would take ages - quicker to remove the screen ! ) and a reciprocating saw which probably has too long a throw. The pneumatic hacksaw looks a damn good idea and a very useful addition - it's now on the shopping list

Other stuff that could act as a heat barrier - bentonite powder (clay) mixed with a little water, asbestos rope if you like living dangerously (might still get it from plumbers) ,silicone rubber - will get to 300°C before burning and safely decomposing to silicon oxide. And there's another refractory oxide the name of which I can't remember (but I'm sure a quick google will find it) mixed with sodium silicate ('water glass') will set quite quickly to a refractory surface which can be chipped off after the job is complete.

Vermiculite (expanded mica) could be added to silicone rubber to make it last longer.

rmattila · Post by **rmattila** » Wed Jun 01, 2011 11:55 am

That particular hacksaw model has a 9,6 mm stroke, which is pretty optimal for cutting automobile panels:

http://www.biltema.fi/osteri/osteri.cgi ... yhmaid=144

Post by **mat_fenwick** » Wed Jun 01, 2011 1:33 pm

Nice work (although the colour isn't a perfect match

) Looks like I was not the only one doing welding this week...