Fiberglassing a floorboard

[Guest]

My floorboards, unfortunately, have a mirade of pinholes in them. My own fault. I left the jute matt in too long for about 6 months and ruined some perfectly original floorboards. I have two brand new Heritage floorboards sitting in my storage room, beging me to install them. At this point in my life, I am not ready to repaint my car, not yet anyway. The next time will be a color change, hence pulling everything off. I am not ready yet. What I would like to do is to fiberglass my floorboards to the perimeter, just shy of the edges. A previous TR6 that I owned had this done (20 years ago) and it is still holding up. I checked the current owner recently and it looks ok. I want something interim that will seal the floors nicely and delay the inevitable. What does the process consist of, what materials should I use. I know that it is a good fix, albeit not really desireable, and I would like something that will allow me to cruise with abandon. The rest of the body is truly "rust free".


Bill

 

[tomshobby]

Bill, this is going to sound nuts at first glance but bear with me.

To prep the floor for repair and remove ALL of the rust without removing ANY of the good metal use toilet bowl cleaner. Then rinse with clean water to remove most of the acid then with a solution of baking soda to nutralize the remaining acid and then again with clean water. Then dry with a hair dryer or similar heat source.

Think about it, toilet bowl cleaner is made to remove rust stains with out damaging the plumbing.

I think it uses muratic acid to accomplish this. Muratic acid will eat rust but not effect good metal. When done you will have a rust-free surface to apply whatever you want.

If you don't believe what I am saying just try it on a rusted piece of scrap metal. I think you will be amazed.

 

[jimttx]

I had a similar problem with my TR7 DHC. I used the repair kit from POR about a year ago it seems to be holding up just fine.

 

[Bugeye58]

Bill, if all you are concerned with is filling the pinholes, why not consider using thick, epoxy floor enamel, after all the prep work? It'll fill the holes, and dries as hard as nails. I know it isn't structural, but then, neither is fiberglass.
After I had the body dipped on my GT6, I had pinholes in the drivers floor. Otherwise, the metal was as solid as a rock. I sprayed it with two part epoxy, and it turned out beautiful.
Jeff

 

[TR6oldtimer]

Pin holes mean your floor boards are already rusting from both sides. No matter what you put on the top, it will not stop the rusting from the bottom. That said, sealing the top from the effects of water sitting on it, will give you a lot of time and enjoyment before they really need replacement.

If the floors still have integrity, I would not use fiberglass as it is a mess to apply, and a mess to remove later. As stated earlier on this thread, POR has a product that will do the job. I have used SEM Rustshield for the same purpose ($25/qt). It is highly viscous and easier to apply and cleanup then POR.

Whatever you use epoxy, POR, or SEM the better the metal prep the longer it will last.

If you find it necessary to use fiberglass, there are many kits readily available at auto parts, hardware, and marine stores. The instructions are straight forward. You may want to practice on something other then you car as mistakes are really a pain to cleanup or correct. Anyway, fiberglass resin can be applied directly over properly cleaned metal. If reinforcing is needed, lay down the cloth and apply a couple more layers of resin, working it into the cloth and working out the bubbles. It's done. Just make sure you protect your skin and use an respirator designed for fiberglass.

 

[jayhawk]

I think if you're going to replace the floorboards later anyway, the fiberglass is a good option. I used to do this with old daily driver VW bugs for myself, my kids cars, etc. It really is easy to work with. Used it to repair boats too.
Prepare the metal, cut the cloth, mix the resin and paint some on the surface using a disposable brush, add the cloth and paint some more resin on top of the cloth . Smooth the cloth and let it dry! After it hardens you can sand it or add more cloth/resin if you need. As noted, protect your hands and ventilate the work area.

 

[PeterK]

Rather than using fiberglass cloth, I recommend using Tiger Hair or Duraglass. It is strands of fiberglass hair embedded in resin; two part with hardener. Relatively easy to apply, just like bondo really, but is a fiberglass resin product that sands smooth and can be used for pinhole patching. Great results here. Ask at your autobody supplier.

 

[MDCanaday]

If you want to save these for a while DONT use any polyester based product.Clean it ,get as much rust off as you can, but remember POR 15 likes rust, and will stick better to it than clean steel. when it has dried, use some epoxie(there are many of them)to fill the pinholes that didnt fillup with POR.....
Of course latter when you replace them with the shiney new ones, you will marvel at how you wasted so much time and money just to procrastinate a few years....(hey we're all human!!)
MD(mad dog)

 

[bobh]

Bill,
I say go for the fiberglass. I can offer a couple of tips learned from repairing my first TVR and a couple of boats. There are a couple of choices for the glass material. Mat, cloth and "hair". Mat is thin random strands of glass. Cloth is woven and comes in various weights. The hair type stuff is basically cut up mat or even powder. I've used tiger hair. When I ran out I used an old pair of sissors to cut up some mat. Mix the hair with resin for your first coat. I mixed mine kind of thick so that it wouldn't run. This mixture will fill in all the nooks, crannies and corners. Next put on a layer of mat. Mat will follow the contours pretty well. Cloth is stiff and will not follow the contours very well. For the final layer use cloth. If you apply more than one layer of cloth you can angle the pattern of the weave to increase the strength. The strength comes from the cloth. The mat and hair are basically fillers. If you want to finish the top of all of this put a final layer of mat on top.
The neasest trick I picked up is to lay some Saran Wrap over the glass/resin as soon as you finish applying the resin. Resin will not stick to the saran wrap. You can smooth out the layer, work out the bubbles and in general get a very nice surface on your layup. Pat the saran wrap with your palm to help distribute the resin. Just be careful not to get a wrinkle of saran wrap caught in the resin. After about 45 minutes you can pull the saran wrap off. Using the saran wrap eliminates a bunch of dirty work. There will be no sharp peaks, random strands sticking up and almost no bubbles.
Use acetone to clean your brushes.
West Marine has a good selection of materials. Clean everything real well before applying the glass. You can seal the fresh metal with epoxy etch prime. I agree with MD, use epoxy resin. Make sure the resin and hardner are fresh. I used some old stuff a few years ago and it never cured. Don't know if the resin or the hardner goes bad, but it was a mess.
If you do a good job with the glass you should get several years (if you want) out of the repair.

 

[kodanja]

the saran wrap idea is great!!

 

[skikir]

It't too bad someone does not make a vacuum formed plastic piece to put down for temp repairs or as a preventative piece. Seems many LBCs get rust in the floor and would be a lot quicker and easier to install.