Hole/crack in passenger floorboard

[joshwilson3]

....

 

[tcxd40]

I have done many repairs on c4s just as you show.

I have used fiberglass matting for the repair with multiple bonding products. FUSOR makes a great product for repairing SMC. I have also used a two part expoxy for boats that is also very good, forget the name though. I have done entire floor repairs and many corners too.

The basic repair is just like a true fiberglass repair only using bonding agents and or epoxys designed for SMC.

tcxd40

If you want I'll send a PM with pictures from some of the repairs I've done.

 

[tcxd40]

Sorry for the late response.

The entire damaged area was removed using a die grinder and all cracks were drilled at the final stop point if you will. This keeps the crack from spreading. The crack it self was widened to remove all loose fibers and any dirt. An area about 1 1/2 to 2 inches around the damaged area was cleaned and prepped to the bare surface.
I'll send some pics later today.

tcxd40

 

[tcxd40]

You can get many types of grinding wheels at most hardware and auto stores that work in a drill. The problem is access, drills are alot larger than die grinders.

Be prepared for a shock on cost. To repair the damage correctly alot of work is required and most is labor and time consuming. Find a repair shop that works with Corvettes and does proper repairs. Check with other vette owners in your area and checkout who they have worked with in the past. I have found shops that work on vettes and do terrible work! One reason I do my own work, however I do have a back ground in autobody and mechanical work. Have run my own company for many years.

You can save alot by removing most of the passenger side interior yourself it is not difficult to do.
Last repairs I did on a 93 coupe invlolved the entire trans tunnel both, front corners and the floor pan attaching points that were broken. On that particular job I used the two part epoxy, which I can not remmeber the name, I'll call my buddy and find out what it is.

Project took about a 60 hours, when you added up the time. We worked on it in the evening and on the weekends, cost was approx. $1100.00 and for that I also fixed the rear floor pan where it was caved in by misplacing the jack. Common problem with the C4s. You'll know if you have this issue if you look from the rear through the window. If your seats are tilted toward each other to the center of the car the pan is damaged. This was for a friend of mine so cost was alittle cheaper. Cost for another car with similar damage was around $2000.00. Of course the area in which you live will dictate cost could be cheaper or more expensive. You can get it done cheaper I'm sure but will it be done correctly.....
tcxd40

 

[tcxd40]

Here are some pics of damaged areas repaired.

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[tcxd40]

I guess if you know when and who did the damage you could file a claim with thier Ins. Most of the time it's found later when the car is up a the rack. The rack can be another problem if the arms are no positioned correctly. Last 93 I purchased the dealer did a great job of crushing the floor!! I also got the car real cheap after that.

I'm not sure about the plastic piece on the firewall you mentioned, is it the insulation?

As far as grinding wheels any small head wheel with the 1/4 shaft will work. The colors I use are pink, white and gray, never bother to notice the grit. I have found the small cylinder shape, torpedo shape and long pointed ones work best. You may want to consider a Dermel kit, the larger ones, it will have all types of wheels and cutters that will work very nicely.

 

[tcxd40]

Unless your a real purist, cut the section out that needs to be removed. It is alot of work to remove the entire insulation, it runs from one side to the other, The entire dash and console needs to be removed to get it out in one piece. Cut it with a utility knife where you have access then use gorilla tape, not duct tape, to join it back together when put it back in.

 

[tcxd40]

Well depending on how bad the pan is and where the damage is located I have found that a treated 2x4 about 2 feet long works great for the large deformations and a 5 to 6 pound sledge.

Then for the small stuff hammers and dollies. You don't need to buy body hammers although they will make quicker work. Any hammer should work, best would be a ballpein hammer for the average Joe and a small piece of steel for the dolly will work also. To get into tight area like creases I use flat punches and large screw drivers.

Shown are a few pics of damaged areas repaired. As you can see the floor is punched in about 3 inches. Time to repair about 4 hours that does not include prep and painting.
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[tcxd40]

Josh,
They don't look that bad. I've repaired alot worse. It will take some time, however you should get most of the dents out with ease as they are not too badly creased.
First and second pics, those close to the edge will take so time this is were you should use a hammer and dolly or similar setup. Once you ge the shape back you can fine tune with a hammer and punch to get the harder to reach area.
Pic three good canidate for the 2x4, fit it above the dented area and give it a wack or two should respond fairly well.
Pic four should allow the use of the 2x4 also just don't hit it too hard or you will push the floor board the other direction and really distort the floor.

Overall you can handle to repair with good results.
tcxd40

 

[tcxd40]

I use several tools to clear/clean away the area.
Carbide grinder bits work best for getting into small places and cleaning cracks. These can be used in a drill or electric/air die grinders. Small air grinders with 2" to 4 " discs work well for overall area preparation, 36 - 80 grit works best. The pads you speak of are similar just not as abrasive, even though they are rated in the same grit. Small wire wheels that attach to an electric drill can be used to ruff up the area also.

You do need to open the crack to allow the bonding agent to get in and do its work. You should also apply the mat to both side of the repaired area. That being inside and outside.
Corvette companies like Ecklers and Corvette Central offer the epoxy to repair the SMC. One of the epoxys that I have used in the past is West Systems.They have several types available. Only draw back is it's fast setting time. Must know what your doing with this stuff.

 

[tcxd40]

Any 1/8, 1/4 shank grinding wheel will work, they can be purchased at auto stores, hardware stores, Sears?, HomeDepot , etc.

If your stopping at Sears buy a Dremel tool it will have all kinds of bits to work with. They are 1/8 inch shanks so the bits are a little small but they do work.

 

[tcxd40]

The brake lines can be moved out of the way, remove the 10mm nuts on the plastic retainer and pull them down gently retainer and all. I use small blocka of wood to keep them down and out of the way.

As far as the insulation pull it out of the way or cut it back and re-install using gorrilla tape, much better than duct tape.

When making the repair for the holes I have used both methods for applying the cloth or matting. Starting large and working small and vise-versa.

 

[LVMYVT76]

bleach

 

[tcxd40]

Yes, bleach is good will kill the mold and mildew. I would also scrub the pans to remove any dirt and scum that has gathered over time.

You mention the bits for metal and or wood, does not matter your working with SMC, either type of bit will work just fine. The carbide bit that I use are for metal, they chew right through the SMC.
tcxd40

 

[tcxd40]

The bit size should be determined by the size of the crack and how far it extends to either side of the crack. In other words a hair line crack would use a small bit, a large crack will require a larger bit. However you can use a small bit for both it will just take longer to clean it up. There are two types of cracks to repair those that are only in the first layer or two of the SMC and those that go clean through the to the other side.
If the crack does not penatrate the other side use a bit just large enough to clean it out and removed any loose fibers. If the crack does go clean through it is best to clean both sides up and remove all fibers from both sides. This will more than likely break through leaving an opening if it does the repair is no different than repair for a hole. I repaired on floor board in which the owner drove over an object that split the floor in two. Once cleaned and ready to repair I used a Fusor product, 145 I think, just for SMC, that is flexable, very strong and makes a permenent repair.
From what I saw in the pics you maybe able to remove the exhaust shield to gain access to the damage. I have also removed the plate on the front of the floor pan. It is both glued and screwed as they say. It's really held on with 5 rivets and alot of glue. However this is not something a novice should try. They are rather difficult to remove without damaging the floor board itself.
As far as the carpet is concerned make sure the jute backing is completely dry. Other wise mold and mildew will be back.

 

[tcxd40]

Don't worry about the roller, if you were repairing a body panel then it would come into use. Soak the mat well and all should be fine. Just remember to work timely once it begins to set otherwise can't work with it effectively.

Keep in mind temperatures both hot and cold plus humidity will effect the curing rate/time.

 

[tcxd40]

Starting on the inside is your best bet. What I do is clean both the outer and the inner area in which the repair will be made. I'll use duct tape to make a form for the repair on the outside most bonding agents once cured generally will not stick. You can use waxed paper and tape it to the outside too. This provides a backing for the mating so it won't fall thru. Depending on the type of bonding agent/epoxy, temperature and how much hardener you use curing time can be anywhere from 10 minutes to an hour. The West system product cures rather fast and can be worked within 15 minutes or less.

As far as the cracks that you may not be able to access on both sides you can clean and dress just one side. If you have access to the crack on the inside clean it up good to get all loose fibers and dirt out. Then ruff up an area about 2 inches on either side, coat this area with your expoxy resin first then lay over top a well soaked mat about 1 1/2 inches wide, centering it over the crack so that you have about 3/4 of an ich on both sides. Let it cure, clean up any ruff edges, blend in to the surrounding area , prime and paint.

 

[tcxd40]

Josh,

That prep work is great you should have no problems with making a good strong repair and you thought this was beyond your skill level. So far great job!

To get a better bond you can drill out the rivets for the shield. The shield is glued on so it's not going to fall off. Go to the hardware store and buy some new 3/16 rivets and re-install them. You can also drill out the rivets for the mounting tabs and do the same and re-install them. If you do drill and replace the rivets be sure to seal the rivets ends. The replacement rivets will be open ended not true blind rivets as the factory uses, you can buy them from auto supply shops but they are expensive .

As to the floor pan, if it were aluminum repairs would be very difficult. Takes a good bit of skill to work with and weld aluminum.

 

[tcxd40]

Pulling the shield off is no fun, takes time and patience. The shield maybe either steel or aluminium. The steel version will stay intact where as the aluminium type will bend like crazy. The glue is extremly strong, normally the glue sticks to the shield and pulls the SMC fibers off in sheets. You may get lucky as I did on one project where the glue did not hold very well. Once the rivets were drilled a quick wack with the hammer on the putty knife and the shield fell off.
I use a very strong putty knife to separate the shield very carefully trying to get the blade between the glue and the SMC. As you can guess there is not much room to work this. The flat portions are fairly easy to work it's when you get to the bend when the fun starts. You may do even more damage in trying to remove the shield depending how deep the cracks are and what type of impact that area has taken. A hard impact will shatter the SMC internally and still look solid on the surface. Pulling may separate the SMC even more.
You can use the same epoxy to adhere the shield back
into place.

 

[tcxd40]

Ok, I think I'm gonna leave the shield alone. Sounds like alot more work than just unbolting it. Plus, it would probably be my luck that I'd bend the shit out of it.

My main concern was fixing the hole to keep the weather out. Its probably been like this for years, and I've only had someone in the passenger side just a few times in the last couple of years. So, I don't have to worry about someone getting in and out of it all the time. Plus I don't drive it a whole lot anyways.

If I don't fix it all, will the damage keep getting worse from the places I didn't fix if it is shattered inside? Or does all the damage normally happen at the time it was jacked wrong? I'm guessing all the cracks formed when it got jacked wrong, vs. more cracks appearing as time has gone on?

Oh, and I'm not gonna use Epoxy. I'm gonna use 1 quart of Evercoats SMC resin with 3M fiberglass mat. It says to use 1" to 1.5" line of hardner with 1 ounce of resin. Do you have any idea how much hardner I should use? The temp will be in the 60's, so I want to use enough so it hardens all the way, but I wouldn't want to have a really short pot life. I believe it said on the can it dries in 30 minutes.

The damage that you are repairing at the front is generally not from jacking up the car although the front pan can be damaged from misplacing the jack. Most of this type of damage is from something impacting the front floor pan. Almost anything from a shreaded tire on the road to a dead animal that was run over. I had a customer run over a parking barrier and did a tremedous amount of damage to the SMC and the steel floor pan. As it looks your preparation and future repairs should provide a sound base. Age, vibartion, heat and cooling can cause stress cracks anywhere.
If you are inclined to look you may find that the drivers side floor at the exhaust pipe that is close to the floor pan(trans tunnel area) the SMC is melted to a certain degree.
Bonds can weaken over time creating stress to adjacent areas. Unless you are out pounding on your ride, drag racing or autocross I would not worry to much.
Placing the jack in the correct placs on the car should prevent any future cracks as you will be lifting the entire car via it's rails at the corners or at the front crossmember or differential.

One other item that you may want to check is the floor pan edge where it meets the steel side rail,(front door pillar along side of the seats.
Alot of cracks appear due to the factory not glueing or correctly riveting the floor pan to the rail, water can enter from this too. I repaired a '93 in which the edge of the front floor pan was not glued or riveted.

I don't have any experience with Evercoat SMC resin. However working with other products the cooler the weather a little more hardener, and just the reverse in warmer weather. The product should also state the best temperatures to work in.