Door Card Repair Suggestions

[EuroFighter2003]

Now I know this topic has come up a few different times on this Forum (as well as others), but I am in the process of refitting the cardboard-like door card panels to my car. I didn't realize how bad of shape they were in, and am having particularly a rough time with the area right where the window switch is located. Pictures below:

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Any suggestions on what process I could use to restore this area? I was thinking using some sort of glue, a drywall mesh tape, and some clamps to reform the general shape of the affected areas. Additionally (as seen in the third picture), part of the Vinyl has started to come off in the same area. Any suggestions for an adhesive that I could use here?

Thanks,
Drew

[t36]

I've done some upholstery work and used a lot of contact cement. The barge stuff stinks and works great - wear a respirator as its really harmful. Follow the instructions of letting it cure before applying pieces together. If you press pieces together before the solvents have evaporated, it will ruin the surface by bleeding through.

As far as reforming the paper card frames, I'd be inclined to experiment with either saturating some cardboard with epoxy and curing it in the shape you need. Then trim it up and contact cement it into place. You are essentially adding a spine to hold shape.
You could probably accomplish the same thing with some thin alluminum, plastic, or any other material that you could bend to shape and glue in.

Fibreglass would work great too, or any mesh and epoxy. But I would definitely make something that has the contour you want first, and use it to make the door panel follow.

[samaritrey]

For my door panels which were in terrible condition I coated them in fiberglass epoxy.
Didn't even add any fiberglass and it worked quite well to make them pretty strong.
For the door push pins I used metal washers to reinforce the holes as most were pulled through.

Finally around the window switches I found a 3d print which I was able to glue (maybe it was Jbweld) which made the door switch trim go on perfectly. If I can find some pictures I will add them.

Here is the 3d Print I used for both doors (just have to mirror for left side) . https://www.thingiverse.com/thing:4325506

[EuroFighter2003]

Thank you for the 3D printing suggestion, I will have to look into that. The 3D printing options that I currently have access to only allow PLA printing. Not sure if this will hold up over time but I hope that I can combine this material with an epoxy base to really strengthen the area.

Any ideas on specific brand epoxys that I should be looking at? Additionally, any glue suggestions that I could use to reconnect some of the Vinyl to the door card backing?

[Tom]

Thank you for the 3D printing suggestion, I will have to look into that. The 3D printing options that I currently have access to only allow PLA printing. Not sure if this will hold up over time but I hope that I can combine this material with an epoxy base to really strengthen the area.

Any ideas on specific brand epoxys that I should be looking at? Additionally, any glue suggestions that I could use to reconnect some of the Vinyl to the door card backing?

From experience, PLA is not good enough for interior parts for any typical summer climate (anything over, say, 80F outside and the interior will warm up to the point of warping PLA). Oodles of people on facebook who will print whatever for peanuts and/or if you vow your eternal allegiance to Carpokes and name a pet after me, you might be able to talk me into printing something for you in ABS or whatever...

[Damo]

Thank you for the 3D printing suggestion, I will have to look into that. The 3D printing options that I currently have access to only allow PLA printing. Not sure if this will hold up over time but I hope that I can combine this material with an epoxy base to really strengthen the area.

Any ideas on specific brand epoxys that I should be looking at? Additionally, any glue suggestions that I could use to reconnect some of the Vinyl to the door card backing?

PETG-CF holds up to heat quite well and is easy to print. Just need a hardened steel nozzle as the CF fibres are abrasive. That said, I've printed parts using Overture PLA+ earlier this year which I'll replace when they warp, but that hasn't happened yet (Sydney Australia and currently summer).

For the epoxy, look for something that's used for fibreglass/carbon fibre as these are lower viscosity and easier to wet the material and soak in. That's what I used for repairing mine. It was just a generic product that I found from a composites supplier. Epoxy glues are thick and more difficult for this kind of job.

[Tom]

For my door panels which were in terrible condition I coated them in fiberglass epoxy.
Didn't even add any fiberglass and it worked quite well to make them pretty strong.
For the door push pins I used metal washers to reinforce the holes as most were pulled through.

Finally around the window switches I found a 3d print which I was able to glue (maybe it was Jbweld) which made the door switch trim go on perfectly. If I can find some pictures I will add them.

Here is the 3d Print I used for both doors (just have to mirror for left side) . https://www.thingiverse.com/thing:4325506

I printed the thingiverse model for @EuroFighter2003 and will be quite interested to hear how they work. If less than great, I might do my own version. There are some real gems on thingiverse, but you have to fight through a lot of 'unpolished' models (ahem) to find them. Time will tell which category these fall into. Thingiverse only has one side posted, so I mirrored the part on the printer so there is one for both sides.

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[Zirconocene]

I'm doing some of this work right now so I feel like I can contribute.

For general reinforcement and future-proofing I'm a big fan of the Bondo fiberglass resin. It's cheap and you can find it most anywhere. I have friends who really like the West Marine 2 part resin/epoxy but those are significantly more expensive. I've done a number of doors with the Bondo materials and they cure up great and reinforce things well.

ETA: Just to clarify, I use the resin without any fiberglass, unless things are particularly deteriorated and need significant structure built back up. Generally speaking, it's just using a bristle brush to paint on the resin/hardener mixture.

For the delaminated portions I would suggest the following: get some polypropylene (think: milk jug material) or polyethylene, essentially anything that super glue is bad at sticking to, and using a clamp of some sort use it to mask the area you want pushed back into shape. If it helps to visualize what I'm talking about is a door card sandwich: door card in the middle, PP/PE on either side of the repair area (and extending well beyond), some rigid support material on the outside of the plastic (like paint sticks), then the clamp. Once those areas are relatively close to how you want them to look get some super glue (and if you have to buy something, search for low viscosity options) and start dropping it into exposed door card material. Go slow! It won't light anything on fire but it is pretty exothermic and will release some gross fumes from the setting of the super glue. Let that set, with multiple "coats", until you don't see any more being absorbed. Then, having built up some structure within the door card material, coat everything in epoxy or resin to provide a barrier to water (super glue is not typically great with water).

Anyway, that's what I do.

Good luck

[Zirconocene]

Since I missed part of your question, for the vinyl, 928 folks generally recommend the red Weldwood, or HH-66, to reattach it to the door card. Same with carpet, if you find some of that, that needs to be re-adhered. I've typically found that the vinyl comes up pretty easily so you can redo significant portions without damaging the vinyl, if you're so inclined.

Good luck

[chrischrischris]

Like you wrote in the first post, to repair the cardboard I used drywall mesh tape and a water based glue and it worked great for me.