Why you should fix the rust on your hatch

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

C

CDN_Cruiser

10 Year 15 Year 20 Year
Joined
Mar 27, 2003
Threads
69
Messages
1,055
...or be happy that you have none.

I bought the truck three years ago in fairly rough shape - good for me as it was relatively cheap and allowed me to spruce it up with the right parts and tires (eg new rotors, pads, synthetic fluid, etc).

At that point there were no real rust spots on the tail gate, but within a year I had quarter sized dimles that have expanded to this point:
115_1529_2.webp
115_1526_2.webp
 
...the body shop pulled the glass today to show how extensive the damage is. As speculated the real fault is that the hatch shell is only pinched together with a bit of spot welding all around the window. This lets water seap in around the seam and rust out the interior.

Given the degree of damage I'm likely going to spring for a new one. I'm also going to have them pay to weld the seam shut - like they should have done at the factory. All of this, as you can imagine, is VERY expensive to get fixed.

If you see any rust, you should pop the window and have it treated ASAP. If you live in a rust prone area and you don't see any rust, you may want to consider having the window taken out to have a look and fork over some $ to have the seam welded shut.
115_1534_2.webp
115_1536_2.webp
115_1539_2.webp
 
how hard is it to remove the glass? is that a body shop only deal?

is there even paint on that metal under the seal? or did the rust originate between the sheets and spread from there?
 
There is a method outlined in the FSM, but the body shop got a glass company to come and do it (price out the cost of replacing the back glass and you'll see why). They only charged me c$80 to remove and install both windshield and rear hatch - but you also need new seals, etc.

There is paint, but it's all eaten away. I thin the water creeps around the seal and then up to the pinch where it sits, and rusts.

Cheers, Hugh
 
Given the cost to fix, I'm doing both!

If your rust is along the window trim I would pull it now while you can save the hatch. If it's just rust spots, you're probably ok.

Cheers, Hugh
 
this would make a great faq if someone tracked down the info on the pinch weld for that seam either here or on the 80's list. :D
 
mmmm, I get the hint (or I'll take pics of mine being welded)

Cheers, Hugh
 
CDN_Cruiser, I do not know how much the rear tailgate is to purchase but, just in the hope it helps, that rust in those photos, in my opinion is not anywhere near enough to replace the entire tailgate. If that existing metal is thin, those spots can simply be cut out with a cutoff wheel, and new metal welded in...its not that hard especially since most of those bends can be bent on a vise. If the existing metal is thick enough, scuff sanding it with 80 grit, and then hitting it with Eastwood's Rust Encapsulator will stop the rust and save some serious money...this only applies if the metal is still somewhat stout there. As far as welding that entire seam, again, in my opinion, that is alot of time and alot of trouble, and possibly harmful. You can get the same result by taking some masking tape, masking off 2.5cm of seam around the seam of the metal, and then hitting it with 3M seam sealer using a 1" foam brush. You can put this on thickly and evenly and make it look lovely. This will effectively seal the seam without the time, trouble and cost of welding that entire thing shut. The other problem is that with welding, you will heat stress the entire thing, this can cause warping, it can also cause problems on the inside of the seam as whatever rust preventative process in there will be burned off. I would not do that. If you are in Canada you can get an amazing product called Krown Rust Inhibitor. This stuff is a light oil that works its way into the tiniest of crevices and prevents rust. In Canada they even have Krown shops that apply the product throughout the vehicle as scheduled maintenance. Dont get me wrong, replacing the thing, if affordable, is the fastest way to fix, but I would not weld anything after that, just seal it and/or soak it regularly with Krown. HTH.
 
Turbo:

Thanks for the advice - that's very helpful. The pics don't really do it justice - there is rust around a substantial portion of the hole where the glass fits. The bottom is the worst, with rust that has effectively chewed away at most of the base and has done quite a nice job on the pinch portion. The top has similar, but not as extensive damage. The worrying thing is that the rust is now inside the hatch itself. So, while they could cut it all out and reweld (which is what they were going to do and which is what they are doing to parts of the front).

The new hatch is expensive, and if I had more time I probably would have taken the time to find a used one in the US in very good condition and have it shipped up.

I do plan to retreat with rust stuff (did it 2 years ago - will now do it every year). I'll look into the 3M stuff, I have been talking about trying that as well with the gey at the shop.

Cheers, Hugh
 
CDN_Cruiser said:
Turbo:

Thanks for the advice - that's very helpful. The pics don't really do it justice - there is rust around a substantial portion of the hole where the glass fits. The bottom is the worst, with rust that has effectively chewed away at most of the base and has done quite a nice job on the pinch portion. The top has similar, but not as extensive damage. The worrying thing is that the rust is now inside the hatch itself. Cheers, Hugh
Click to expand...


Yes, rust is almost always wildly worse than it looks, after reading about rust in other areas I agree replacing is the way to work it, however, I still think that welding that seam shut will take too much time, trouble and money, and would be harmful in the sense that the tremendous heat generated, even if they stitch the welds, will warp things and burn off any galvanizing or other protection on the tailgate. The seam sealer, IMHO, is much better. One of my many many many interests is in restoring cars, so rust is something I see more of than I want to. Whenever I see rust, I see shortcuts in fixing it as well as ways to over-fix it. I think shortcuts are always an aggravating thing in the long run, at the same time, I think over-fixing things can also cause headaches. I remember on one of my classic cars, I spent over thirty hours fixing the underside of the trunk floor...this was located directly above the gas tank so no one would ever see it...I was so determined to cure the cancer of rust that I went way way way over...I guess I get the satisfaction of knowing that that floor is perfect, more than perfect, but still I see how my obsession was overkill! If you replace and then try to prevent future problems, that is the most sensible solution. HTH.
 
grrrrr, maybe someone in the US can start a class action that I can join ;-) ....this seems to be such a design flaw...Although now that I'm doing this, I could see buying that truck for a DEEP discound given the damage (but knowing the 'rust problem' is really only on the hatch for this truck) and just replace the gate.

Turbo, the guy I've been working with talked to the welder who agrees with your point. Too much stress for a new part, etc. Now we just have to figure out what else to do aside from the regular window seam install. I've been debating about trying to use 3M marine bedding compound to seat the window gasket - not sure it will work on steel - I've usually only seen aps with fiberglass or wood

Can you recommend and product?

Cheers, Hugh
 
I would not use something designed for wood and fiberglass, metal is harder to bond to,

If it were me I would use a 2 part epoxy aircraft sealant like PR-1422 probably in the thinner “A” variety , not sure where you would get it or how much it costs, I am sure there is something in the Automotive field that would do as well and 3M probably makes it ,
 
Wow CDN - just noticed in your sig line that it's a 97. Definite geographical impact. My 91 showed no signs of rust when I sold it, even with mildly salty winters here.
 
Hugh,
Have you talked to your shop about using a generic seam sealer (urethane based) ?? I agree taht welding will disrupt more of the e coating on the inside of the door than it will help. the other thought would be to use corrosion protection applied my a whip, this is typically used in frame rail ends on unibody vehicles. F@rd uses it a lot on rocker panels and the new exploders actually have the rockers full of a type of this product. I personally think some of this applied formthe inside will be your best bet, coupled with a urethane based seam sealer on the outside next to the glass.
Dave
 
Dave:

The body shop has said 'they have some good stuff' - w'll see.

Semlin - it's factory original. I did a search in the 80scool and I think I can resolve a number of different theories based on looking at the damage:

1) It's unlikely that it's a 'bad batch' of hatches
2) It's not caused by clips
3) It's not only if you have replacement glass

Based on my past 'polls' and looking at the damage - Most likely - if you live in a region where they use a lot of snow removal chemicals (salt, etc) then you may have a problem. It's not wet/rain, but the nasty environment from the wet + snow + wiper fluid + etc that is slowly working around the rubber trim and gasket and up to the pinch where it seats and eats away the hatch. Lower is fine.

I also have damage on the top of my front windshield (which was replaced very poorly by PO and is likely part of the source of my wet carpets). Interestingly, there is not pinch in this location and the rust is not in the seem like it is in the back.

Cheers, Hugh
 
Hello,
I'm bringing this back to the top. I have the same problem (I'm in Chicago) on my 97 FZJ80, and I am 1) looking for a replacement, and 2) looking for the best way to prevent it on the new one.
So, for 1): are all years interchangeable with 97? Also, what years are tan (two tone desert and moonglow pearl) available?
For 2): this thread seems to say that a chemical seam sealer before window installation, and a gasket sealer after installation, is the best way to go. Is that still the group opinion, and what products has anyone found to stand the test of time, if any? Or can I only go by reputation and brand-name (and cost)?

thanks,
Kenton
 
You must log in or register to reply here.

Share this page

Back
Top Bottom