Grp floor panels?

Been off the MGB for some time. I kinda gave up when I ripped out the fcarpet and found I could see through the floor.

It is now officially next project in line after my dalek. [OK I also have a clock to build but that is an inside/rainy day job].

So now I have to fix the floor. Only the car is no longer drivable as there are no seats and so it will be a tow truck to and from the body shop.. and .. and..

I am trying to work out how to proceed next. One option is to go round the local body shops with a picture and see if they will quote on that. Another is to learn how to weld and do the job myself. And another is to cut our all the rust and fill in the holes with the same GRP process I am using for my dalek.

Anyone care to tell me how big a pain it is going to be to weld in new floor panels??

Also what sort of welding gear will I need? Is a plasma torch essential or would a sawzall and grinder suffice? Is it the type of tool that can be rented?

get it done by a pro since the floor is a serious part of the structure of the car. no GRP, use steel. the panels are about $170 per side, all cut to shape and size. But look hard if the floors are gone the rails and rockers my need to be looked at. They all tie into each other for a strong frame called uniframe or monocoque.

If you are that good with body work and a weld or mig torch it is a challenge. Ask around of other classic car owners and they will send you to a reputable technician oppps body shop. It is at this point when some of our memebers that love their cars want to cut corners on repairs because of perceived high costs. Done once by a pro, properly sealed and it lasts for a real long time.

Talk to Blake. And, you could drive it with a cushion.

Yes, you can do this if you are motivated to gain new skills.
1. You will need about $600 worth of equipment. A 110V mig welder, 4-4.5 inch Makita or Dewalt grinder, good hand drill, chisels, putty scrapers (for breaking welds), many,many 1/4 drill bits and other small stuff.
2. The floors are "spot welded" in place. About 1 inch spacing all around the perimiter, crossmember, and frame rails. All these have to be drilled or ground out and broken loose before the floor panel will come out. This is the real Hell of this job. Many of the spot welds will be visible after you clean the area - I use red scotchbrite and Berrymans Chemtool spray to do this. BUT, if there is a lot of rust, the welds will NOT be visible due to corrosion obliterating the indentations that are so obviously weld sites. This is where it gets really shi...y. Even though they dont show I promise they are still there. It amazes me how strong even horribly corroded welds can be. You will have to hunt for them and break them. How you ask? With the drill. BUT.. you only drill out the floor panel on top, NOT the flange below it. You must leave this to weld the new floor panel to. Drill through the top panel and break them apart with the chisel or putty knife. WEAR GLOVES and get a Tetanus booster shot from your Doctor before you start this! Sometimes you will have to use the grinder for the stubborn ones.
3. Clean up the flange areas after removal.
4. Drill the new floor(s) with the 1/4 drill with the same spacing as the original all the way around.
5. Plug weld the holes to the flanges at about 70 -75 amps. Grind smooth.
6. Might take you 40 -50 hours for the first one, about half this for the second.
7. Hard work, but then you will be salted and ready for harder jobs. And you will be free from body shops to do these repairs in the future. If I was doing this for some one I wouldn't touch it for less than $500 a side - more if the flanges were rotten in places - like yours are probably going to be unfortunately.
8. Good luck - cheers!

Regards, Jon

Do as Etype728 wrote, but go to your local auto parts store that deals in paints & body panels & buy the proper cutting tool mandrel & some extra cutters to cut those spot welds. Cost you about $20 & a lot less work. When using the cutter, first drill a 1/8" hole in the middle of the weld for the pilot pin of the cutter mandrel. then install the mandrel on your drill & cut only into the floor pan, let the cutter do its job or you will break off the teeth with to much pressure. It's easy to get the hang of it. When you install your new pan you can cleco or bolt the pan to the small hole you drilled for the pilot pin. You will easily fill these holes when you weld in the new spots.

OK, this is starting to look like I go down the weld in new floor panels route.

I had forgot the bit about the floor being structural :-)

Looking through the boards, some folk have added in additional cross members to increase stength.

While I am not going to encourage you to do a full fiberglass floorpan, I have to wonder how much strength the floor adds to the unit body.

Other than keeping your butt off the road, I am not so sure how much the floor adds to the structure. The MGB has a substantial framework along the perimeter that takes care of most load bearing needs.

Now, as to your other problems; I had to wiki up "Dalek" to see just what the heck you are up to:

>The Daleks are a race descended from mutant Kaleds from the planet Skaro and >encased in mobile shells.


Dude, rusty floorboards are the LEAST of your worries.........


Pete

here is a link on floors

http://miller-garage.com/modules.php?name=News&file=article&sid=11&mode=&order=0&thold=0

I may get ripped for posting this, but there is a product call Fusor that could be used to glue the floors.

http://www.lord.com/Home/ProductsServices/Adhesives/FusorAutomotiveAftermarketProducts/Products/MetalAdhesives/tabid/3400/Default.aspx

Daleks... not mutants, but a biomechanically engineered race made by Davros... thought to be extinct after the mutually self-destructive war with the Time Lords.

"We must exterminate... exterminate... exterminate...."

Lee:

A few years ago, I would have flamed you for even suggesting the adhesive route. However, since then, I have been looking into the products. I think I would have a hard time defending my knee-jerk reaction of "It can't possibly be as strong as a weld".

I am more inclined to think (due to the surface area involved compared to spot welds) that it might be stronger than spot welding in new floors. IF DONE CORRECTLY.

The thing with adhesives is that it is all about the bond line and surface prep. If you get the flanges clean enough, straight enough and clamp the panel in place tight enough, you are golden.

The cost of the body adhesives will make your eyes bug out. The dispenser is as much as a cheap welder. Not having used the stuff, I do not know if you have any work or wiggle time to place the part or if it is a one shot deal.

Pete

Do an archival search on here for FLOORBOARDS. This has been talked to death.

Every single detail has been documented over and over and over again.

If you want some pictures, I can provide with with all the pictures you need, just send me your email in a PM, and make sure its a broadband service so that you can receive a large file. Yahoo, or aol reg accounts won;t work.

If you go to Harbor Freight, you can get a MIG Welder for $100, a Grinder for $10, and all the darned cold metal chisels you need.

You can get all of the tools needed for less than $200. Before anyone starts saying that the HF tools are cheap, I will respomd with YES, they are cheap, and if it wasn't for the fact that they were cheap, I wouldn;t have every single tool that any moron could ever think of using. - They DON'T break, they're reliable, they're just not made in America, if it matters!

Your floors will cost about $125-$200 depending on the type.

You have to somehow separate the existing floors from the rest of the car. There's many methods, I found cutting the majority of the floors away with an angle grinder with a metal abrasive blade, or a sawzall to be the best, then I got a whole slew of really sharp cold chisels and sliced all of the spot welds apart. NOWadays they have a better method, using a spot weld cutter. These are also available from HF and they work spectacularly, they will cut out the spot weld, but leave the metal underneath, which is far better than a regular drill bit, becaue you do not want to cut BOTH pieces of metal, only the top floorpan, not the metal it sits on.

Once you remove all the floor, its just a matter of drilling some spot weld holes in the new floor, trimming it to fit, and welding the holes up. The floors sit nicely on the metal sills that surround the floor area.

If you like doing projects, this isn't a hard one, its just kinda messy and tedious.

Learning to weld good enough to weld the floors back together is easy too.

B

Caveat emptor if having it done by a "Pro". Most body shops are in the collision repair business, not the rust repair business. I was shocked to find what kinds of shortcuts and bodges the alleged "pro" used on my roadster (datsun). Rust holes filled with bondo, metric screws forced into SAE threads, the list goes on. This was a reputable body shop too, not a shade-tree mechanic. If you learn the skills and put in the time, you can be sure of a sound job being done. And your next Dalek, or maybe K-9 can be made of steel!

That's why I suggested that he talk with Blake, who I believe was the first here to post on using FUSOR to install floors. That was years back with no issues reported.
I'm of the school that doesn't see the floor boards as a structural piece so much as a covering anyway.

Ya, I'm not really sure that they're so structural either.

They're pretty darned flimsy, The car structure is perfectly sound WITHOUT floors, so I'm not too sure that they're all that structural either.

I'm sure they add some rigidity, but, I would think that plexigass, or oak as is in many, many cars floorboards would do the trick too.

Look at all the cars that have wooden floors, granted many actually have separate frames, but, I don't know if all of them do.

If I knew anything about fusor, I would comment, but, I have absolutely no experience with it. They use it on cars nowadays, but, they designed to use it, so I don;t know if that makes a difference or not.

B

Buy a good secondhand welder - there are plenty about and just try before you buy. Often you'll get some free wire with it too.
Hiring is a good option too. MIG s are easy to set up and use once you're used to them and if you're all ready to go you can weld the two floors in a day so only 1 day hireage.

Paul ;-)

Fusor? Do a search. It's been discussed several times before.

My previous comments:-

Derek:

I tend to agree that the factory put the panel there for a reason. Also, as an electrical engineer, with almopst 25 years since the last statics course, I am out of practice.

But here is a fun one to do; fire up the solidworks program, doodle up a square structure made of closed beams. Toss in a bit of a cross support structure.

Now run the FEA on this with and without the skin on one side. Where it helps the most is if the force is put on opposite sides running parallel. (As if you were trying to make a parallelogram out of a square) Kinda like a front quarter head-on collision.

Does not seem to do much in a side impact.

Does hardly anything in torsion. As a flat panel it can't.

Now, just for fun, put a second skin on the top. By "closing the box" Things get a lot better. Perhaps we should be crawling under the cars and adding a second set of floor panels UNDER the frame rails?

I realize that this is a gross oversimplification. But I see the MGB frame as very similar to the MGA only welded to the body, and it works just fine without the floors in place.

Pete

So what would be the practical downside to carefully done GRP floorboards?

Rictus Wrote:

They probably put it there because it is cheaper and lighter than wood, and tends to keep road spray out. The firewall, tunnel;, rear shelf, crossmember, and the sills are where the structural strength are. Which is why we find examples where someone has used a sheet of plywood for flooring, yet the doors don't sag or pop open going around corners.
Look at a Lotus or VW bug sometime.

Derek up North Wrote:

Lee Wrote:

Rictus Wrote:

One thing that was not mentioned was to carefully check the rockers for rust. This is the structural area you should be worried about. If the floors have bad rust there is a good possibility that the rockers need work. I would verify that the rockers are good before you start working on the floor. The cost of replacing the rockers will be high and may direct you to getting a better MGB then dumping loads of cash into the one you have.

LORD Fusor Metal Bonding Adhesives shall only be used for bonding metal to metal (steel or aluminum) in full or partial panel replacements of:

- Doors skins;
- Roof skins;
- Quarter panels;
- Rear body panels;
- Other outer body panels.

LORD Fusor products SHALL NOT be used for bonding structural components such as rails, pillars, rocker panels, core supports, etc. If in doubt as to what is a structural component, contact the vehicle manufacturer.

I am going to have to go with the floor panels as falling under the "Other outer body panels" on this one and take it as acceptable by Fusor. If it is good enough for a quarter panel, (as stated by Fusor) then it will be much less of a compromise on a flat floor. The quarter panel actually sees a bit of stress since it does close off a box.

My main objection would be because it is an unkown to me. I don't give any inspector as much credit as others insofar as realizing that the panel is bonded rather than spot welded. I serioulsy doubt any inspector is going to dig into your seam sealer to inspect the method of attaching the floor panel; once they see that it is nice solid tin they would be done.

Pete