There is a crack in the floor panel on the passenger side of my '87. Its about 2" and roughly L shaped. Now to be honest I am quite suprised its not worse! How do I fix this? Is it difficult? I bought new carpet and before I have it out in I want to fix those cracks. Thanks!!

 

I'd recommend the SMC resin by Evercoat. As the C4 is made from SMC and not typical fiberglass. The Evercoat SMC resin has extra stuff in it to help it bite into the SMC.

Depending on where the crack is. You'll need to grind the inside and outside. Some cut a V into the crack to open it up. Then you mix your resin and brush it into the mat. Then brush the resin onto and around the crack before you lay the resin/mat.

Though, yours doesn't sound too bad. Some have had cracks running all over the place that would be a pain to grind the whole floorboard.

 

josh is correct about both materials and technique. Be very, very careful with any attempt to "V" the crack. Your floor is not as thick as you might guess.

 

Drill a 1/8 inch hole on each end of the crack & maybe at the 90 of the L to stop it from cracking more before you glass it in. You don't have to V it if you clean & ruff it up real good. Should be an easy fix, make sure you seal it real good with undercoat & paint.

 

Drilling the holes are a good idea. If you want to V the crack, the floorpan is pretty thin so be careful. I would make sure you overlap the crack at least an inch on each side with new FG mat. Most fiberglass kits available at parts stores will say if they are compatible with SMC. If the kit does not specifically mention SMC, go with the product Josh suggests. Paint the finished repair with paint, not just primer to make sure its completely sealed. SMC isnt particularly porous but the repair may be. Paint will take care of it.

If you dont know, there is a whole section here devoted to paint/body. Look up at the top left for "Forums", hit the drop down arrow, click "General", then select "Paint/body" There are some pros there with great advice.

Good luck!

 

your not the only one who found a crack this weekend

 

Hope you just hired a plumber!

 

WOW - I will get a kit and the recommended resin to start... I have never done or seen this done, is it difficult? any special tools? U guys know everything...

 

it's really not hard, just take your time and wear gloves and a mask. I fixed my floor by cutting a piece out of my salvaged vette's floor and fiber glassing it in. Never used fiberglass before in my life and it came out pretty good.

 

One problem I've noticed when these get jacked wrong which causes the cracks. Is it can cause strange firewall leaks. As it can cause seams to open up which would let water in. And it can loosen up pop rivets enough to let water get in past the pop rivets. You have pop rivets at the front of the driver floor pan where water gets dumped from the cowl.

After you rip the carpet out. I'd do some good high flow water leak testing by sticking a hose in the cowl at different places and letting the water flow for a long period. And check for water getting in at both driver and passenger floorboards from the firewall.

 

Do I put the resin / mat on both sides of the floor board meaning the inside and under side?... Also assuming I get it right the first time... Thats a big assumption. Is their a drying -curing process? If so how long? Will I be able to drive to work the next day. Finally, what do I finish this repair with... Is their something I put over the resin as a protectorant or in the resin enough? Thanks

 

Make sure you do your water checks first.

You'll want to get Acetone to clean. You'll want to wipe it down with Acetone before you grind. And after you grind. And before you lay the resin/mat.

They say it is best to do the repair on both the inside and outside. But at least do it on the inside as that is the hard part as you have to rip carpet out. You'd want to do say the repair on the inside first. Let that cure which I think takes a few hours. Maybe longer but it should say on the can. Then grind on the outside and do the repair on the outside.

This is what I used to grind. Some 2" grinding discs from Lowes. You buy the discs and the base plate they screw into. Then put that in your drill. Though, it does depend if you can easily get to the crack with your drill. Alot like to use an actual grinder. But that costs more. I forget the grit used:



Some use a Carbide bit like this to help open the crack up some. You can get it at Lowe's:



After you do the repair on the outside. You can sand it down some to try and blend the repair in. I sprayed the inside with some flat black paint. And on the outside I used some rubberized undercoating spray you get from the parts store. There already was an undercoating spray already on the floorpans. So, it blended in.

After I brushed the resin into the mat to completely soak the mat with resin. I used something like the edge of a paint mixing stick to tap out the excess resin and air bubbles. Then when I layed the fresh resin/mat on the floorboard. I again used the edge of a paint mixing stick to tap out excess resin and air bubbles and to make sure the resin/mat made good contact with the floorpan. You want to try and squeeze out all the air bubbles. You'll want to do multiple layers of the resin/mat. I cut out all the layers of mat I planned to go with and stacked them on top of each other. Then I completely soaked the layers with resin. That way I could do it at one time instead of doing one layer at a time.

 

I got to tell you, I am thankful for your help - everyone. I appreciate your detailed descriptions which tells me you really love these cars but I got to tell you; restorations on these beasts aint easy! When I think I am finished with one thing I find something else! I've decided when I am done this car will no longer e a daily driver. I know I will likely never sell it so I am going to make what I've always wanted. I will put ip pics when I am done and I feel confident about the glass work - its similar to to working with wall plaster tape and water, at least thats the approach I am taking!