Fixing rust in the trunk

[Robroy]

When I once got my car a few years back I noticed some surface rust under the trunk carpet. It wasn’t so bad so I thought I’ll deal with that later :rooleyes2:.

A few weeks ago after I had been on car show where it had rained, I cleaned the car up and also emptied the trunk since I know water sometimes leak in there. It was at that point I realised that the surface rust had grown rather much since the last time I peeked in here :Dou:.

[Robroy]

I first tried a wire wheeling but wasn’t happy with the result since I couldn’t get the surface clean.
After some thinking I decided to go for sand blasting which from my experience is the most effective method to stop rust. It is a mess though since you need to cover up absolutely everything including yourself to protect from the sand to enter.
I used aluminium silicate this time which turned to be less dusty than ordinary sand and bit more effective too.

[Robroy]

My strategy was to work on a limited area at the time, blast, clean and then put on the primer.

[Robroy]

Had some rust on the RH QP inside too, might as well fix that also.
I get in water here when I power wash the wheel well, haven’t figured out where it get in though. I tried putting a lamp in the trunk with a completely dark garage to see if I could see the light trickle out somewhere, but without result :confused4:.

[Robroy]

All primed up!
I used an expensive but highly recommended primer.
My experience is that it pays off in the long run

[Robroy]

And finally the painting! :beers:

[Robroy]

I found these plugged holes under the LH taillight, I assume they were made to run the propane lines through when the car was converted to that during the 80’s…but I don’t know for sure :confused:

[Bob Alberini]

It looks like you did a very nice and thorough job, Per.

[Gum,beest]

And finally the painting! :beers:

Don't want to nitpick on your work
But why didn't you fixed the back as well before you painted the floor
For the rest :xyxthumbs:

[Robroy]

It looks like you did a very nice and thorough job, Per.
Thanks Bob, that means a lot coming from you!

[Robroy]

Don't want to nitpick on your work
But why didn't you fixed the back as well before you painted the floor
For the rest :xyxthumbs:

I assume you are thinking on the brown spots on the back?
They are not rust, its rests of glue or paint, I’m not sure which...
Besides, I didn’t paint the back since I plan to put the carpet back on there again

[Robroy]

Next step is finding the places where the water leaks in to the trunk, BEFORE… putting any carpets and cardboard back on place.
I plan to consult a neighbour to operate the water hose spraying on the car while I’m lying in the trunk with a flashlight....

[Gum,beest]

Per
I thought that much after i had posted my remark

How is your parcel shelf?
Is it possible that you have a leak in the rear window seal and it leaks from there in to the trunk
Other places i suspect are the trunk seal or the taillights

[Robroy]

Per
How is your parcel shelf?
Is it possible that you have a leak in the rear window seal and it leaks from there in to the trunk
Other places i suspect are the trunk seal or the taillights
Yeah, the rear window has been on my mind too as I’ve understood from other members it’s common for water to leak in that way.
However the cardboard on the package tray shows no signs of water, I had that off installing the speakers, and the window looks to have been sealed up thoroughly from outside. After washing the car it’s typically wet in the rear of the trunk, never in the front.
Trunk sealing looks intact; I’ve been thinking about replacing it anyway since it’s old and may have lost its elasticity.
I adjusted the trunk lock shackle yesterday so the trunk lid will close a little tighter, fingers crossed that it may help!

[Smartin]

Look at the mounting holes for the vinyl top trim.

[Robroy]

Look at the mounting holes for the vinyl top trim.
Hey that’s a good tip Adam, thanks! I haven’t thought of those.
I will keep an eye on them when I do the water test

[The German]

Nice work, Per ! Seems as if you have a professional equipment for rust fighting.:xyxthumbs:
Hope you´ll find the hole from where the water comes into your trunk looking for a possibility having some fun with a beautiful Centurion ;) .

[73 Centurion]

Nicely done!

I've done smaller versions of this kind of work and it always takes way more time than I expect. Masking everything off, getting the equipment lined up and general prep take time to do it right like Per did.

We love our cars for their impressive size. I'm sure Adam was thrilled to have trunk that could swallow a Buick big block. (The first twin engine Centurion). That size is less wonderful when you have to go over the surface inch by inch. When you've worn yourself out with prep and doing the work you have to deal with clean up and painting. I've seen many projects like this left in primer because they ran out of weekend or energy. Many p0eople don't realize that many primers can absorb water and promote rust if they aren't top coated when they're dry.

This job is well done. Per was lucky that he caught this while it was still surface rust. Good primer and paint will allow the trunk to withstand some water without rust starting.

The factory did not always do a good job of painting floors and trunks. This poor coverage made it easy for rust to begin. The thin layer of carpet does not stop heavy objects from scratching through the paint and can hold water against the metal. It's understandable why trunks have rust even in Arizona.

A layer of truck bed liner or a cushion under the carpet can help the paint live longer. The thin padding used for floating wood floor systems is good for this. It doesn't trap water under it. It doesn't absorb water and hold it against the metal. The cushioning keeps the paint from getting scratched. If you can find someone who installed one of these floors they inevitably end up with extra.

Just a thought to preserve the wonderful work you've done.

John

[Robroy]

Thanks John and Rolf for your encouraging comments!

This type of project is indeed time-consuming. I have been working several evenings with it; after supper I got into the astronaut suit and then kept going until 10- 10.30.
My compressor started to stall one evening and still do sometimes now, think I may have had it going a bit too long than it is designed for.

This Monday I did the water test and have now found where the water leaks into the trunk.
Bob Alberini has been right all the time; the water leaks in under the window (see the pict where I have circled the area).
Drops streamed down the inner part of the wheel wells like riding a rollercoaster and then ended up at the rear part of the trunk. It was mainly on the right side but a little on the left side as well.
My very helpful neighbour in charge of the water hose suggested me to cut off the inner part of the window sealing (on the inner side of the window metal trim) with a carpet knife and then reseal it with transparent silicone (same as used now). It seemed to leak as most when he sprayed on the window rather than around it, so there is a tiny hope it will at least reduce the leak.
I think I will do a little wider silicone sealing than the one there is now, also the current looks old and has loosened a little, especially on the right side where the leak is worse.

Plan B will be to have an expert doing a total reseal of the window which will involve rust repairing and probably also a new vinyl top. This will cost me big bucks for sure; I don’t dare to think how much at the moment….:Dou:

[The German]

Oh, that´s somewhat tricky, Per. As you know I´m a fan of oil and grease for such cases. The advantage is that the oil will reach every hidden gap and rust filling it and surrounding it so that any further corrosion will be stoped for years. You have to keep an eye on and press in some graese again after some years but you will have minor work and a maximum of success in fighting the rust. If some years later you want to repair the greased parts you only wash the grease away with hot water and some soap before starting the work - easy again.

In your case I can´t decide if it could be a really good solution b/c I only can see your photo, but as far as you informed us I feel sure I would do it this way : Let some specail* oil run into the holes after the car is dry and after letting it settle down some days press in some special grease* (*:The oil and grease has to be designed for rust preventing and it has to be sure that it will not eat the rubber of the window seals !). The grease will close the hole and in combination with the oil the grease will be an active rust-preventing-system. My experience with such a method is good. BTW: if necessary you even could cover the grease surface with silicone (= better to have some mm hard surface outside). This method is an easy and cheap one and will reach the aim !

If you don´t find the richt oil / grease in Sweden here you will find it:
http://www.korrosionsschutz-depot.de/de/katalog.html - If necessary I would help you getting the correct ones!

I´m curious about how you will march on fighting against that very special problem, Per. - Goood luck !

[73 Centurion]

Hi Per,

It's good to know what the problem is. You might want to remove the trim and get a better look at what's going on. It looks like you've got enough rust to allow a leak, but you don't know if it's pinholes or something bigger.

You might be able to stop the rust with a rust encapsulator (like POR15) and seal the area with filler. It will hold up fine as long as the rust is stopped and the rear window can be sealed to your repair. If the work is limited you might be able to gently peel back the roof, make your repairs and re-glue it in place. If welding is involved you'll have a harder time saving the roof.

Whether you use oil and grease or something more involved the quicker you stop the rust the easier the final repair will be.

In any case it is obvious you're taking a methodical step by step approach. Diagnose the problem, discuss your options and pick the solution that fits your situation.

John

[Gum,beest]

On another forum here in the Netherlands
A member had done a test with bare metal treated with a variety of anti rust chemicals and leave them outside during the year
I believe he tested the stuff Rolf mentioned also
He found that most of the stuff works but the simple lead primer used on ships works best
It is illegal for private persons to buy here in Holland but still widely used in the offshore business and other countries
A other he recommended is Owatrol don't know it is available in Sweden
This stuff is mixable with primer or paint or on its own but needs a topcoat to be real effective

[The German]

Ovatrol is good for parts which have surface rust. It goes into the rust b/c it´s a fluid thin like water, then it drys out it covers the rust like a transparent paint. It´s a little bit flexible so that there will be no new cracks in the surface even on parts which have stronger vibrations (for example the cars doors). Ovatrol is a combo of oils and resins and these can be influenced by water so that in the long run (some years) the new surface will be washed away; that´s why the Ovatrol-protected parts have to be painted / covered with normal paint as Erik told us. This stuff is recommended to use on weather exposed surface-rusted parts which are difficult to clean up totally from rust that they could be treated in the normal way. I used it for some parts in my cars doors.

For the problem Per has I would not recommend Ovatrol, in his case I would do it as I told before or in the way John told us about b/c it´s a region with hidden rust and with possible water influence. So if you take Ovatrol one can´t be sure that all the surface can be covered by paint after it´s flooded with Ovatrol. And Ovatrol is inactive after drying out while oil / grease keeps working for years b/c it does not dry out - every new gap will be filled with oil / grease - that´s why I love this method. Okay, the best is ripping all apart and restore the rusted parts in a way that they are back to be nearly new, but that also is the most expensive method. Where it´s not really necessary I always chose the cheaper / easier method which stops the rust. This way the situation will not walk further to the bad side but she is not back on the good side again - that´s clear. One have to have an eye on those parts and act again if necessary.

[Robroy]

Thanks guys for all advice and suggestions on how to tackle this!

At the moment I’m thinking on consulting a car glass shop with experience from older cars.
My neighbour’s son has a 71 Porsche; he consulted such a shop in the neighbourhood regarding similar problems and was very happy with the result.
Step one will be to call them.

I’ll keep you posted on how it develops…..

[Robroy]

I’ll keep you posted on how it develops…..
I called a highly recommended automobile workshop that specialise in old American iron yesterday and told them my problem.

They presented two ways to go:
1. Take off the window and weld/repair all rust, then put the window back and reseal it. This would very likely have to include a new vinyl top as well.

2. Take off the metal trim, remove all old and loose sealing/filling material, then reseal with a new sealing/filling material and finally reinstall the metal trim.

Alt 1 was that best way to fix the problem permanent, but could obviously easily run into big bucks.

Alt 2 wasn’t that cheap either, but I understood that this is a very thorough shop that takes their time to do a good job rather than risk their reputation.

Alt 2 feels that it wouldn’t be that hard to do yourself if it wasn’t for how to remove the metal trim around the window correctly, and then reinstall it back on again to look as good as before.

Has anyone here done this and can offer some advice? They mentioned something about a special tool for GM window trim of this age…

[Smartin]

Here is a photo of one...

http://www.maverickcomet.com/TechArticles/RemoveWindshield/window_trim_tool.gif

Even if you can remove the trim yourself, have the shop remove the window and reseal it.

[Robroy]

Thanks Adam,
I am concerned how much rust there is around the window, as can be seen below the vinyl is very uneven in some places.
I was thinking of removing the vinyl trim so I can peek in there to see if its rust or filler that makes the vinyl to lift

The workshop I contacted are closed for a few weeks anyway, there is a car glass shop with experience from older cars that I was thinking on calling as well…

Happy holidays btw!

[Smartin]

Ohhh, looks like you've found the problem! You might get lucky and not have to buy a new top if they can peel it back and save it when the rust is fixed.

You're experiencing the worst characteristic of a vinyl top. They are rust catchers!

[Robroy]

I have somehow under the years I’ve owned the car managed to suppress how bad it could be under that bubbling vinyl :o.
The rough edges seems very odd in their structure which has made me sometimes doubt if it is all rust under there or something else like filling material, wishful thinking probably….

But as you say Adam, if the major rust is on the lower parts around the window I might get lucky so they can save the vinyl top

For starters I will try and loosen the trim to peek under the vinyl at that corner of the window, then the bitter truth will be exposed :Dou:

[Gum,beest]

Per
That photo got me worried
I am sad to say that on the forum here in Holland a guy had bought a very fine looking 75 Cutlass
And he had some bubbles under the vinyl
This is a fine looking car he bought

3041

See the horror underneath the vinyl

3042

And what a good sheet metal guy can do with it

3043

So i am really hoping that this is not the case with your car

[Robroy]

As Adam say, these vinyl tops are rust catchers.

My bubbling is only under the window at the corner shown on the pict, hopefully the rest is fairly ok, but you never know….

[73 Centurion]

Hi Per,

The seams between the quarter panels and the filler panel beneath the rear window is one of the areas of our cars that is prone to rust. Looking at that picture I'm afraid you're going to need to have the rust cut out and new metal welded in. I'm sorry to be the bearer of bad news but I can't think of anything that would cause that bubbling that won't require welding to repair.

I suggest you buy the trim tool Adam suggested. I've seen a couple of variations on the tool. On the cheapest end of the scale it's just a flat peice of shaped metal with hooks. Avoid this version. There should be a step between the handle and the part with the hooks. Some of the clips are very difficult to remove if you don't have this step. If you have access to a salvage yard that has some older cars I recommend you take the tool and practice. If you're lucky you can get some backup trim peices in case something goes wrong.

It takes some finesse to apply enough pressure to release the clip without bending or breaking anything. A little bit of practice and you'll get the hang of it. You can learn without damaging the cars, all you'll be doing is making it easier for someone who wants that peice of trim.

The way the factory installed vinyl tops promote rust. Cars destined for vinyl roofs did not have properly painted roofs and the trim was often punched through leaving exposed edges. If you remove the vinyl, fix the rust and have the area properly painted a new vinyl roof will not be anymore prone to rust than a normal roof. You are not doomed to always having rust.

We know our cars so well we tend to focus on what needs to be fixed and occasionally loose site of all of the things that are right.

Let us know what you find.

John

[Robroy]

Hi John,
Thanks for all your good advice and sorry for my late response.
Very interesting to hear about the seam between the quarter panel and filler panel being a weak spot to stand rust.

I’m afraid I have no salvage yard with cars like mine here but I do understand your idea, and it would have been a very smart way to get some practice if I had.

While I was spending a few vacation days in my hometown I went to a workshop owned by an old schoolmate that has a solid reputation when it comes to bodywork.
He said that to do the welding the window definitely needs to be taken off which if you think of it is pretty obvious. He also pointed out the risk to crack the window when taking it out or reinstalling it. Could be wise to have a plan ready how to get a new window if that should happen was his point.

I have been thinking on a middle way to take care of my problem;
1. Remove the vinyl & window trim and then the window itself
2. After that carefully peal up the vinyl so far that all the rust under the window can be welded and taken care of.
3. Then put the vinyl back on its place and install the window and all trim.

Since my vinyl top seems to sit very tight everywhere else (apart from under the window) and show no tendency to have any uneven metal under it, this could be a good enough repair for my use of the car IF it can be done without ripping the vinyl.
If that happens I will of course fix all surface rust while the top is off.

One thing I have been thinking of is if I can get a new vinyl top with the correct grain and seams as the stock one? And if so what does it cost?

[Gum,beest]

Per
I think it is also advisable to look for a rear window if any available before starting the work (perhaps a Electra window fits?)
So if anything happens to yours a backup is available in a short notice

[Robroy]

I’m currently struggling with getting the lower vinyl trim off, found four nuts in each corner in of the trunk.
Does anyone know where I can access the rest of the nuts?

[Robroy]

Managed to loosen the vinyl so much that I could peek into that bad corner this evening.
There were two holes big enough to put a finger through; you can see one of them on the last pict.
I imagine it will be similar on the opposite side; the bulging is much less there though.

So in all it doesn’t appear to be that bad although welding and body work is needed for sure

The vinyl came loose rather easy btw

[75RivGS]

Rest of the clips are possibly a clip-on system (same as on a Electra?) Those are plastic ones and a bit brittle so carefully pry off the trim. They do have a front and back side so look closely how they are attached on the pins.

[Robroy]

Rest of the clips are possibly a clip-on system (same as on a Electra?) Those are plastic ones and a bit brittle so carefully pry off the trim. They do have a front and back side so look closely how they are attached on the pins.
Thanks Rob!
Just what I needed to know :xyxthumbs:

[Robroy]

I suggest you buy the trim tool Adam suggested. I've seen a couple of variations on the tool. On the cheapest end of the scale it's just a flat peice of shaped metal with hooks. Avoid this version. There should be a step between the handle and the part with the hooks. Some of the clips are very difficult to remove if you don't have this step. If you have access to a salvage yard that has some older cars I recommend you take the tool and practice. If you're lucky you can get some backup trim peices in case something goes wrong.


Is there any of the preferable one’s currently listed on ebay?
I’ve seen a few different styles of them but feel a bit lost which to go for….