Hole/crack in passenger floorboard

[tcxd40]

The area in which tends to get soft and melt is the center of the floor pan just as it forms the trans tunnel and slightly above, right where the exhaust pipes are routed.

As far as the plugs are concerned everyone I have encounterd are loose fitting, from what I have been told this is to allow moisture to escape. If you give me a day I maybe able to get a part number.

And yes you are correct about the lifts if they are not postioned properly they will damage the floor pans. Like I stated earlier that is how I purchased my wife's '93 so cheap. Dealer crushed the rear floor pans.

 

[tcxd40]

Your repair looks good, should hold with no problem. You should prime and paint the repair on the inside it will protect the repair surface. Any spray can primer for automotive finishes will work. I use alot of Dupilcolor products for small repairs just as you are performing for underbody work. Rubberized undercoating is good, however I have found that Dupilcolor truck bed spary on liner is great. Comes in a regular sized aerosol can.
It has a very durable surface when cured. I then spray with rubberized undercoating afterwards.

 

[Schrade]

Before I get to grinding. I will need to clean up the floorpans as water had been leaking under the carpet for years causing a musky odor. I had pulled the floorpan carpet back on the driver and passenger side, and they are soaked.

So, what would be good to use to kill the mildew on the floorpans and on the back side of the floorpan carpet? Lysol?

Keep the bleach in the laundry. Use ethyl alcohol. Pour it directly on the carpet. It will dry to no residue, and nothing will grow in the moisture as it evaporates.

Bleach is loaded with electrolytes (salt - sodium hypochlorite), and will start an oxidation reaction on metal just by the vapors.

 

[Schrade]

On those bits, what shape am I looking for? Something with a wide V or U shape, or a narrow V or U shape? And I'm guessing I'm not supposed to go all the way through the crack, just grind it out some? I do believe some of the cracks go all the way through as I think I was able to see some on both sides last time I looked.

And I also plan on doing the repair on the outside as well. I think I'll be able to get my drill/grinder to the hole part and on 2 of the cracks. Though, I may not be able to get to the vertical crack. So, what I can't get my grinder to, I may just sand it by hand the best I can. I'll have to put a thick layer on that hole on the inside since I'm gonna grind on the other side and lay mat. Don't want to go through it.

I may go for something like Lysol. As it also mentions killing odor causing bacteria, etc. As not only is there the mildew, but also the odor as well. And I need to clean the back side of the carpet, so I don't wanna get bleach on black carpet. Any other suggestions?

ANY MACHINED edge - preferably a keyhole saw. Machined is the key. You need only to go BEYOND the last end of the crack. A crack is easy to continue, but a machined edge, from a machine cut, makes for a hard point to re-start a crack. The load is spread all the way around the edge of the machine cut.

 

[tcxd40]

I plan on using Rustoleum Universal Flat Black spray can for the inside after I scuff it up. That stuff says you can use it on all kinds of things and specifically mentions fiberglass.

I'm all done on the outside. I just used some 3M rubberized undercoating. My repair does feel solid. I did notice some small air bubbles here and there. Mainly in the thick parts. But I say it should be fine and is 10 times better than it was. I don't see how you can get all the air out as the resin itself has alot of bubbles in it.

Did you by any chance find the part number for the drain plug? I may have to call the dealer back again and tell them to call Chevy to find me the drain plug as I'll need that soon so I can get car put back together. Though, I've got some time as I'll first have to steam clean the carpet and some other small things before I start putting it back together.

From now on, I'm gonna make sure the shops I take it to know how to properly jack it up. Don't want to go through this again, haha.

The repair looks very good, job well done.
Still waiting on my buddy at the dealer for a part number on the plug he is checking on it. If it has a number and is available he'll let me know. A plastic plug like the ones used in other areas of the car will also work in a pinch. Cap plug is the brand I see most used by the factory.

 

[tcxd40]

I think I may have fixed my drain plug. I had to get a chisel and hammer and bang on it. I'll see if it will work tommorrow.

What do you use for heat insulation? I'm gonna need to replace the floorpan and tranny insulation. I have heard of Reflectix from Lowes? It looks kinda thin. But I could pick it up tommorrow and get it cut. I could use my sound deadner as a template.

And how hot do the floorpans get? I went to pick up some paint, but it said not to let it get over 200 degrees. I don't know if the floorpans stay under that temp, or would I need high temp paint?

I kept the original jute floor insulation in both my '93 Vettes on the inside. I purchased some very nice used ones from a Corvette place in Virgina, can't remember the company name, always has Corvette items on ebay. For the outside of the car I chose a self adhesive product from Hiperparts in Ohio. Part #DEI-050502 Floor and tunnel shield. Really nice stuff. This materials is a aluminium faced fibergalss(?) insulation. I cut each piece to fit on the out side of the floor pan, see pics, then sealed the edges with black RTV. I placed this on the underside by the exhaust pipes as it reflexs heat away from the floor.
There is commercial sound and heat barrier products for automotive use, Dynamat is one, however I found them to be too heavy. By that I mean adding more weight to the car. The stuff from Lowes I think is a plastic foil(?) not sure that will hold up to the heat radiated by the exhaust
Don't bother with the high temp paint, regular paint works fine. As you are driving the floorpans stay cool enough it's when you are sitting still and idling that the floor pans can get very hot. Both of my '93s suffered from this. Mine being a former SCCA car sat for long periods of time running. Carpeting in both was melted to the insulation on the trans tunnel and both have heat damaged SMC at the trans tunnel closest to the exhaust pipes.
As you will see in the pictures I have also used exhaust wrap on the head pipes only. This also insulates the pipes keeping the heat away from the floor pan. Being the head pipes are stainless steel there should be no problem with the the rotting pipe syndrome.