Cage Removal - Welded

[rikky 37]

i've got a 6 point Safety Devices cage in the 205. not a problem with most of it, as everything except the B pillar main hoop has been removed (was bolted in at these points)

 

my issue is with the B pillar. at the bases, instead of being bolted, it's been welded (given not fantastically or thoroughly, but enough to cause a removal problem). see these photos:

 

http://www.rikky.net...5/photo%206.JPG

http://www.rikky.net...5/photo%207.JPG

 

i've tried getting a grinder in to the front and back welds, but the edge weld closest to the shell structure is impossible. my other option is to oxy acetylene torch it out but this is going a bit close to the fuel tank on one side, and plus it'll mean making up new box section due to being left with a hole

 

how have others done it? i've tried cold blowing it with a chisel which has worked a little bit on the thin welds. i've tried metal drill bits and spotweld drill bits to no avail.

 

if i was to cut the legs off from the bases, and make up a new base / weld them to the legs, would this seriously hamper the resale-ability of the cage? it needs to be removed as it's going back to a standard road car

 

a welder friend has suggested 'automatic chiselling it' which will be the same as the torch, but no sparks. just don't fancy having a holem would rather cut the feet off but rather not render the cage unsellable!

 

answers on a postcard...

Edited July 12, 2012 by rikky

[Cameron 16]

Don't chisel it out, you'll tear up all the thin sheet metal of the panel it's welded to.

 

Your best bet is to go in carefully, cut 5-10mm away from the welded edge (on the plate welded to the body, not the body itself) all the way round and remove it that way. You'll have much better access to grind / cut out the rest once the hoop is gone.

 

Also, use the thinnest disc you can, and preferably use one that's been worn down a bit. 1.0mm discs are the largest you should use for such thin metal.

[rikky 37]

you mean so i'm physically cutting the cage footplate 5-10mm shorter each edge, thus not touching the welds atall? i did think of this, but the closest edge to the B pillar only has about 10mm between the edge of the cage tubing and the edge of the plate, so if i cut that shorter it'll leave it quite close to the edge of the tubing. i guess it can always be tacked back in place by the next buyer.. hmm..

 

edit> looked at the photos again. i think that might be the best thing to do. my grinder discs are about 1.5mm thick though.. might have to grab some more tomorrow

Edited July 12, 2012 by rikky

[Rippthrough 98]

Grab some 0.8mm slitting discs, just don't push sideways on them.

 

If it was meI'd just cut the bottom of the tube off the plates and weld new plates on!

[Baz 421]

Air chisel? (careful use of - you could easily make a mess!) BIG cutting disc on a grinder? Die grinder? - maybe quite time consuming!

 

I've only ever cut welded cages/mounts from shells that were being scrapped, but if you want the shell to remain then i can understand the issues!

 

If you cut the bases off it would no longer have SD's stampings on them so would probably hamper the re-sale value.

[rikky 37]

so the actual footplates have the markings on? tbh i bet they're obliterated now by the welding splatter anyway!

 

i think he said air chisel, automatic chisel, ah god knows.. i just have visions of an enormous chisel they dig pavements up with and it making a gaping hole in the whole car. i don't like the sound of doing anything to it, i'm bound to make the wrong decision!

 

phil: that's what i was going to do but i didn't know how it'd affect resale, and also refitting.. i guess if i cut about 10mm away from the base or as close as i can, then there'll be enough flex in the cage before tightening the bolts up, to let it all slipo back together won't there? it's not a full welded thing afterall...

Edited July 12, 2012 by rikky

[wracing 19]

Get a 9" grinder and cut the thing off then dress it back to the body with a grinding disc.

 

Thanks

 

James

[rikky 37]

used a 0.8mm disc again on the front and back welds, and agitated the other side welds. It has come out without problem and feet bases intact

[Rippthrough 98]

^Right, now you have to sacrifice a small child to the Angle Grinder Gods to say thanks.

(Don't use a ginger kid, it offends them).

 

 

Should be able to dress the rest back to the shell with a flap disc? (far easier than a grinding disc!)

Edited July 13, 2012 by Rippthrough

[chipstick 382 1 Cars]

Can't you gradually grind the welds down at an angle until such a stage where the cage foot comes away and leaves the spreader plate left welded in underneath?

 

Then do the same with that and stitch up if required.

[rikky 37]

I'll just put my 3mm wheel on and grind them gradually down, there isn't much to grind now

[brumster 135 1 Cars]

If you had lots of time and patience I guess you could have at it with an air die grinder and a ball-ended grinding die, as Baz suggests?

[welshpug 1,657]

flappy discs ftw

[brumster 135 1 Cars]

I was assuming if he couldn't get a cutting disk in there, he couldn't get a flap wheel in there either - but I do agree, they're great at munching away at anything

[Cameron 16]

Never ever ever ever take a grinding disc near car bodywork, use a zirconium flap disc. Grinding discs are for building bridges.

[Rippthrough 98]

I was assuming if he couldn't get a cutting disk in there, he couldn't get a flap wheel in there either - but I do agree, they're great at munching away at anything

 

He's got the cage, the flap disc is for tidying the shell up

[rikky 37]

i've actually found a load of flap wheels but drill bit ones. they seem fairly harsh, might give them a go. i think grinder ones would be better though. what sort of grit? or any recommended ones? been looking on Screwfix etc but some say they don't last very long atall, even on welding seams

Edited July 14, 2012 by rikky

[welshpug 1,657]

they last fine if you dont lean on them, to remove material you want around a 40 grit, to polish up stuff more like 60 to 80.

[rikky 37]

shop near me has only got 80 grit flap discs. Screwfix it is then

[Cameron 16]

80 grit will be fine!

 

As said, they last fine if you don't lean on them, and will actually remove more material for longer that way. 80 grit is about as coarse as you want, it's better to take a little longer and get a good result than to munch through the tinfoil bodywork and make a mess.

 

Same goes for cutting discs, with the 0.8mm ones you pretty much just need the weight of the grinder to make a cut. If you start getting lots of yellow-green dust then you're munching the disc, not the metal. If you don't strain your grinder then it will last longer and you'll be much less likely to shoot off and cut something you weren't meant to (like a finger.. ha) so it's wins all round really.

[Rippthrough 98]

^Buy decent flap discs and you can give them some serious pressure and they last fine - in fact they'll do more work as they're cutting bigger chips per pass - so long as you don't overheat the discs - Never tried whatever s*ite screwfix is selling though - if you have a Toolstation near you go and get 79037, that's a half decent one, £2.98

 

Anyway, anything from 36 grit to 120 grit would be fine for the bodywork, you'd have to be really hamfisted to go through just tidying some welds up with any of them, 60/80's are a good all rounder

Edited July 14, 2012 by Rippthrough

[Cameron 16]

And use them as flat as possible.