New roof box installation - fiberglas body treatment

[Philipp]

Dear all,

My name is Philipp and I'm living in Switzerland, near Zurich and drive No. 10849. It's great to be here and I'm always very thankful for all the good information I got from this forum (even I was only a guest in this forum until today).

My problem with 10849 is giving me restless nights and thus I hope to get further advices on how I can fix it in this thread:

As the T-panel was slightly lifting off of the roof I decided to get rid of the old roof box and install the stainless roof box from delorean.eu. I reached the point where I have removed the old roof box and start with the preparation of the fiberglas-body to install the new one. Due to the fact that in some area of the old box the glue stuck better to the fiberglas than to the metal, I unfortunately locally removed some fibers as seen in the picture attached.

Photo 1.JPG

Now I would like to treat those areas before I finally glue the new box on the body. I got the recommendation just to apply some resin and sanding it afterwards. What do you think? I would prefer to apply fiberglass mats as well, but I'm worried about if the mats get properly attached to the old body and not get loosed when I have installed the new roof box and apply some load on it. Final question: What kind of resin/fiberglas mat is recommended to locally repair the body?

Thanks for your support!
Philipp

[TheDon]

You could use some "dog hair" or shredded fiberglas and resin to fill in the spot or cut a patch from a roll of Fiberglas and resin it into place. I'd let it cure for a few days before gluing the roof box on.

[Bitsyncmaster]

This is what I use for a filler.

http://www.aircraftspruce.com/catalo...ckedcotton.php

I use T-88 epoxy also which I buy from aircraft supply places.

[john 05141]

Hi Philippe,

Bare fibreglass like that needs to be treatet. In case water goes in, it starts a rotting process. So keeping it dry and free of moist is very important.
Next, I would go to a car repair store, you can get fibre and resin there, or better, a boat repair shop. With the big lake near Zurich, you must have some stores like that.
Brand is not important, I buy mine from Voss Chemie but I do not know if that is abailable there.
Small imperfections you can repair with filler too before you add a layer of resin.

Mark the area you're going to repair and sand the whole area. Use a vacuum cleaner to clean all the dust out. Apply a good coat of resin, and apply a thin layer of fibre.
then add a new thick layer of risin. (using a roller, not a brush) Look at some examples on u-tube. Make sure no air bubbles are underneath.

Then sand the surface that is higher than before, and clean and add a final layer of resin only, not too thick. I would add this layer of resin ove the whole roof area.
You have to use good dust masks, and don't go cheap there becasue you'll breath the fibres when sanding and is very unhealthy. I would sand this outdoors if I were you still using dust marks and clean the interior of the car before you bring the car back indoors and remove the dustbag from the vacuum clear too. Peope underestimate how dangerous that stuff is. (I use a throw away coverall too)

Most resins are yellowish in color, I woud add some black color pigment, it looks better.

Jan

[Philipp]

Thanks a lot for your help and advices.

I will try to organise some of the stuff you recommended. As you mentioned there are some good examples on the net.

Nonetheless I'm still a bit worried about the adhesion between the old fiber and the new layer I will apply. My concern is that the load on the new roof box will separate the old from the new fiber as the glue will most probably stick like hell.

Philipp

[JohnZ]

I'm really looking forward to see how your roof box replacement will come out, since I have a bent roof box too and I will have to deal with it in the future.

Welcome to the forum, anyway! We are more or less 500 kms far from each other!

[Josh]

Bent roof box? I have never heard of that before. The main and only issue (as far I am aware) is rust.

[Philipp]

@ JohnZ: Thanks for the greeting. As soon as I'm more or less finished I will upload a kind of lessons learned (or a manual on how to remove the old roof box and install a new one).

@ Josh: Yes and no. Yes, rust is a topic too. As you can see in the picture below the bottom of the roof box was full of rust.

2.JPG

Nonetheless the glue between the roof box and the fiber body has also lost his bonding force and box gets separated from the body. I haven't seen that effect on other DeLoreans here in Switzerland but if you google it there are some owners who have some problems with that. I assume that it will become an issue to each owner sooner or later... In the picture below you see how the box is bending and separates from the body.

1.JPG

BR
Philipp

[JohnZ]

Bent roof box? I have never heard of that before. The main and only issue (as far I am aware) is rust.

I'm talking about the surface that sits right under the t panel, mine is slightly too high in the middle, so it seems like it is bent in its central portion. This has consequences on the t panel too, which is slightly bent too. Anywayt I'll deal with that in the far future!

[DMC5180]

Phillip,

Several years back their was a very nice write-up and photo's done by an owner in New Zealand or Australia. Unfortunately, the info was Lost when DMCTALK.COM crashed.

You will need to remove ALL the old GREEN bonding adhesive. You can try chipping it off the underbody. The person the wrote that article write-up did this with very good success. When the factory installed the T- roof structure they did not Prep the underbody bonding surface. Proper adhesion requires sanding (scuffing) the fiberglass. If you chip the old green stuff off you will notice the underbody is not sanded (smooth and glossy)

Modern day Acrylic adhesives used for metal bonding need proper bond preparation for long lasting results.