defender tub replacement and galvanised bulkhead

[Bigmark]

Hi all, i have been away from this forum for a while due to illness but im back to share (somewhat belated photos) of a few stages where i replaced damaged tub with a new one. Then i bought a secondhand bulkhead , had it sandblasted and now at the galvanisers ( hope it comes back straight enough to fit), photos to come shortly. I have heard of some horror stories with warping but its worth a shot as my current bulkhead was badly rusted in the A pillar and i could have pushed my foot thru the floor..

Anyway sort of thought of taking photos too late in the project but wanted to put up something incase it helps others considering doing the same.

[uninformed]

Good work BigMark,

lets us know how the bulkhead goes with the HDG.

[jboot51]

Yes keep us updated on the bulkhead.

[mark2]

I have galvanised a couple of Series 2a firewalls with reasonable results. Some rippling of the flat sections but no major warping.

I chickened out on doing my 110 firewall and had it sprayed in zinc primer after sandblasting. I think a 110 firewall has less inherent stiffness than a 2A firewall. Not to say it wouldnt be ok, but I decided against it at the time.

It was later suggested to me that a simple jig consisting of a piece of 50mm RHS with tabs welded to it and then drilled to fit the lower firewall bolts would hold it in straight during galvanising. Silicone can be used to stop the zinc locking the bolts in place.

Anyway, hope it works out. A galvanised firewall is a great thing.

[Mettalique]

In terms of warping, it may not be such a problem unless heat has been involved in welding new sections into the firewall. In such a case, the heating of the galvanising process will release the energy built up and may warp it. Generally it won't warp if the item is just pressed metal. I used to do a lot of forge work and stopped galvanising (hot dipped) as the tension release would warp it so instead I'd use hot metal spray in zinc. Same goes for big welded jobs. The only problem with hot metal spray is that it won't get into areas the hot dip will.
On another note, I just love the way these things are like a big mechano set. Great work!

[Bigmark]

Ok i got the Bulkhead back and i have to say i was surprised how good it turned out. It fit straight back into place with only a slight warpy look to top flat section of footwell (passenger side only) and a few little ripples elsewhere , but nothing worth talking about.

First i have to say that it was hot dipped and (on request) not quenched afterward- this may have helped- it was also placed down on flat surface to cool to help keep straight. amazingly the chassis bolts lined up but i had to drill out slag from holes.

Now there is a problem- i was told by the galvanisers to thread tape bolts and wind them into threaded holes. Well most snapped and other turned the capture nuts inside. so i have to now drill them out and tap them. next time i would probably leave them and tap them all out. the main problem ones are the 3 that hold the door closers and the 2 large ones that hold steering column plate- i will have to drill thru to inside to use nuts and bolts as the captive nuts tore out while i tried to turn the bolt.

[red_tj]

looks good mate. can I be so bold to ask about how much it cost to do?

[Bigmark]

well I paid $750 for the bulkhead so I could get it galvanised
before I took the defender apart. I will sell the original bulkhead as is or repaired. anyway only $80 to sandblast, little bit of welding by myself- then $165 for hot dip galvanising. quite reasonable I thought. this was done in perth, prices may vary around the country.

[red_tj]

cheers. thanks for that, the prices seem reasonable.

[uninformed]

Hi BigMark, good work so far mate.

Apart from sandblasting, was there anything else the Galvanizers had you do? I was thinking there may be some sealer inbetween seams that may not be great when dipped? did you have to remove any sealer etc or just blast and good to go?