Fiberglass Floor Repairs on my 89
 

I have just been replacing all the carpets in my 89.

As I removed the front floor carpets I noticed some cracks in the fiberglass on floors.

From a restoration point of view should these repairs been done from the inside of the car or from underneath?

Is this a common situation and should I add some reinforcement while I am add the job?

Any technical suggestions appreciated.

i was under mine and found a hole the size of a nickle so im in the same boat.ttt

there was a thread about redoing the fiberglass floors awhile back
i believe the poster fixed them from the inside of the vehicle.
thanks
matt

It's gonna look like crap if you do it from underneath. I'd do it from the inside.

In order to reinforce it you'll have to add some layers of cloth and resin. It's messy stuff to work with. The best procedure I've found is (after surface preparation), spread some resin on the panel and then adhere the dry cloth to it. Then, with a squeegee, spread more resin over the top until the cloth is saturated and laying the way you want it. Plan on dragging a little liquid beyond the edges of the repair in order to get a smooth transition.

I'm not a professional bodyman by any stretch, but this method works for me.

BUT! if you do the repair, the fiberglass will smell for a very long time. Maybe you can use some kind of sealer overr the resin and lock in the smell.

I wonder if you lay something down like Dynomat over it if it would work for this. It adheres well enough that it should create a seal as well as block a little road noise and heat. Underneath the car after you make the repair you should just be able to spray with undercoat, that should bleand in to hide the damage as well as create a seal.

2 part epoxy could be a good experiment, then dynamat

I went for overkill. My passenger side had multiple cracks, I cut a piece of aluminum large enough to cover all the cracks with some overlap, bonded it in with some resin bought from a paint shop and pop rivets. Used the same resin to lay two layers of glass roving. Has stayed in place 7 years.

were the cracks apparent from the bottom view or did you discover the stress cracks with a carper removal?

do these cracks allow NVH to eminate from below?

There are right and wrong ways to do things. As you can see from posts, several fixes have worked for folks. For me, I have always employed fiberglass or SMC repair techniques of reinforcement on a "backside" and then surface repair on the other side. I had a crushed corner in my floor (and some other bad areas) and I rebuilt them working both sides. Both sides look just like they did before they were broken, no lasting smells and they are essentially undetectable. You just want to make sure you use an SMC epoxy resin and matte cloth and be deligent throughout the repair. Best if you read up on techniques such as Ecklers fiberglass repair book and then use your imgination.

I found them while doing new carpet. Mine were not stress cracks, A previous owner had "bottomed"it on a speed bump.

I hate those previous owners. Course, if they didn't screw up these cars and know it, they'd never be for sale, and we wouldn't get our greedy little hands on them and have so much fun repairing their screw-ups which allows us to make these cars into the cars we think they are,
Hey, never mind, I love previous owners!!!:lol:

my po i talk to on a regular basis, he was #2 me #3, he was very anal and keep up the maintenance, mods were in his taste tho, not mine some of that had to be reversed.

I
 

used JB Weld and am very happy with the results. Idiot "PO" (previous owner) jacked up the car under the seat pans, put cracks and a hole in them, I took my time and make thin smooth layers of JB Weld both on top and bottom and well beyond the cracks and hole, I think now it's stronger than it ever was and looks OK.

I dealt with the same problem on my 86. With suggestions from guys on this forum I used smc resin and fiberglass mat. I did the inside first. paint on the resin, embed the mat in it and saturate with more resin. When it dries I painted on another coat of resin. I then when underneath the car and did the same thing. Make sure you grind out a good sized area around the repair site first. I used heavy grit and an air tool. When everything dried I sanded it smooth, put down heat/sound shield and then carpet. Underneath I sprayed it with undercoat. No problems yet. If you give me your email I can send pics of the whole mess. I can't seem to figure out how to put pics on this forum.

Do you need to sand the areas smooth between applications of matting? and a final sanding after last application?

You want to apply to a rough surface. Too smooth, won't adhere.

please send pictures if you still have them. thanks

I have to do this job too. Looks like something cracked nice silver dollar size hole in the corner of the passenger side foot well. I've worked with fiberglass before, so its no big deal. I planned on doing the repair from the inside with the resin and the fiberglass mat and once that was in place, spreading resin on the outside to seal it up. I figured 2 layers of glass should fix it well.

I did my floor a while back. Mine was cracked on the drivers side on the front edge of the foot well all the way across the edge. Also, along the side, the floor had separated from the rocker. I put some silicone along the side that had separated and used small nuts and bolts todraw things together. Then went to Autozone and got a fiberglass kit and laid in 3 or 4 layers on the front edge and the side at the rocker panel. Biggest thing is making sure that you cut out all the frayed and messed up fiberglass. Laying in the fiberglass and resin in a job like this is not a big deal.