Thread: Galvanizing a chassis

I have done one chassis (IIA 88"), 2 firewalls, 15 rims, 5 door frames, 1 rad panel and countless other small bits.

If it is done properly you won't have to worry about corrosion of the galvanised part for at least 20-30 years (I am talking Landies here, not boats).

Chassis needs to be stripped or blasted before galvanising. The galvaniser will acid/caustic dip and then flux dip prior to galvanising. A landie chassis has plenty of drain holes normally, but depends which end they pick it up out of the tank from - on a series chassis, a couple of extra holes in the dumb irons doesn't hurt. On a coiller, make sure there are holes drilled in the strengthening plates where the a-frame crossmember mounts to the main chassis rails.

Galvanising increases the weight of the chassis by 5-10%

Have had boat trailers done in years gone by, be wise to drill drain holes as they will hang the rails to dry anyway, if you want something to last its worth the work, we had our trailers done in Darwin every couple years

Originally Posted by graceysdad

Have had boat trailers done in years gone by, be wise to drill drain holes as they will hang the rails to dry anyway, if you want something to last its worth the work, we had our trailers done in Darwin every couple years

Question about drainage is how many, how big and where legally? I don't want to weaken the chassis in the process.

Also I have had mixed results about altering the strength of the chassis during the Hot Dip if it is not done properly. I can see how it would weaken it but at the same time the zinc plate would add to the overall thickness, so I can see how it would be strengthened as well. Some folk I have asked say yes it will be stronger, others who have built similar structures disagree.

I'm confused.

Originally Posted by dobbo

Question about drainage is how many, how big and where legally? I don't want to weaken the chassis in the process.

Also I have had mixed results about altering the strength of the chassis during the Hot Dip if it is not done properly. I can see how it would weaken it but at the same time the zinc plate would add to the overall thickness, so I can see how it would be strengthened as well. Some folk I have asked say yes it will be stronger, others who have built similar structures disagree.

I'm confused.

As I said in my post - a landie chassis has plenty of drain holes to start with (more than a boat trailer!).

What you are referring to with strength is the heat of the galvanising process (500oC odd) making the steel more brittle, and therefore prone to cracking. The Landie chassis is a fairly low-grade steel, not to far from mild steel, and the embrittlement problems usually only occur with higher strength steels.

Someone like Dave Blknight would be good one to know how the chassis fare with gal dip long term.

do it, no extra holes are really needed, sound second hand chassis's (how do you pluralise chassis?) before you start as the acid/flux dip will eat anything thats rotton....

weve spoken about this one in person.

I've done two and both were pains because the idiot galvanisers didn't know what they were doing. They have to work out which angle to dip it so that the extra zinc can run out. You don't just drop it in sideways or one end first.

Consequently, the second chassis, (my current one), weighs a bit too much from extra zinc and some parts don't have any zinc and are rusting!

Extra 3/8" holes can help. Drill them in corners where there could be an air pocket but don't go too mad. Unless a hole is drilled somewhere really critical - sorry, I can't think of anywhere offhand apart from around suspension parts - it won't lead to any cracking.

can we do a buy one do one free you buy it and we did our 90 one for free

seriously will watch this thread with interest as the 90 is going to be stripped down and rebuilt and serioulsy considering doing the galv on the chassi as

we only want to strip the pos once