Thread: Project $ 3 K Is Underway

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Don---One of the best things I've ever found for making accurate patterns is my $11 glue gun. When I made the pattern for my T roadster floor, I cut a peice of cheap particle board deliberately about 4" undersize from what I knew I would need. My floor was recessed about 6" (the car was channeled that much) so I couldn't just lay the bottom of the car on the plywood and trace around it. With the particle board dummied into place (off the frame), ---actually I propped the body up on four 8" high cement blocks, one on each corner, and propped the particle board up on four 14" high blocks of wood. Then I took a bunch of 12" x 8" peices of cardboard, and set each peice tight against the inside of the fiberglass body, then glued it to the particle board all the way around the inside of the car. When I finished doing that, I lifted the particle board out, with all the cardboard stuck around the edges. I drew a line all the way around the perimeter of the cardboard, 3/8" in from the outside edge, and trimmed it off with my shop scissors. This then gave me the perfect size template to use when I cut my 3/4" marine plywood floor.

Brian: That is a super way to do it. I have always had a problem getting the exact fit, even though I scribed lines every inch and measured out from there. No matter how I tried, the finished cut was always a little off from the measurements. I will try your method. It sounds foolproof.

I'll post some pictures when I get to that stage.

Thanks,

Don

Hey guys,

In all my years of building cars I have never encountered the problem of the floor showing through on the outside of a fiberglass body. Was I just lucky? What causes this problem? I'm getting ready to start another project and I don't want to trust it to "luck" again...

I've got a book that I bought years ago before I ever did my first glass car, the title is "The fiberglass boat repair manual." Although it relates to boat repair and boat building, fiberglass work is fiberglass work, whether it is a boat or car, so the info in it was really informative.

In that book they say to never lay the edge of plywood directly touching the existing glass (or in our case, the body) because it can leave an imprint on the outside of the body where the new fiberglass work is being done. I think it has something to do with the fiberglass curing and pulling the body to the plywood floor, or maybe the plywood just creates a dark shadow there. I just don't remember the exact reason. But I have watched our fiberglass guy at work replace many transoms in boats, and he always leaves a gap at the edges, and he and I have lightly talked about the need to do that. But once again, I just don't remember the specific reason.

I have the book right here in front of me, and I will try to find the paragraph that discusses that and post it if I can find it before I have to leave to go to the shop this AM.

Don

J Robinson.---I know a million things. About 300,000 of them, I learned from practical, hands on experience, building my own cars over the last 41 years. The rest I learned by reading a lot and talking to people I considered smarter or more experienced than me (they've grown fewer as I've grown older) The bit about not letting interior flooring or firewall or bulkheads come in direct contact with the fiberglass body shell falls into the latter category. Since it seemed to be a pretty well established fact in "fiberglass expert" circles, I have never taken the chance of doing it any other way. Deep down, I believe that it has to do with the different expansion/contraction rates of fiberglass versus plywood.---if you have a peice of plywood 3/4" wide touching the fiberglass body, then it is a "point contact" type of thing, and will leave a "shadow" on the finished body. If you leave a gap, and tie the plywood to the body with a "flange" of fiberglass about 3 to 4" wide, then the loading is spread out over a much greater surface area, and won't leave a shadow.----I think thats it, anyways.

Yeah, I think that is it. Perhaps it creates a hard spot too, where it can't flex and work without causing some problem.

Brian pretty much said why I do it, this is something all the professionals I have seen do, so I just felt there must be a good reason not to question their experience. I tried to find that paragragh, but the book is pretty thick, so it will take me more time than I have today. I will try tonight when I am sitting around, and will post it for you.

This was a great question you raised , though. Thanks for asking why.


Don

Would the flange be T'd on the plywood or more like an angle iron shape. If I understand you are saying you should cut your plywood a little small and then build the flange on to it to the size of the template. Then attach the flange to the body wall.

Thanks for the answers. The difference in expansion and contraction makes good sense. Apparently I was just lucky in the past. I must have inadvertenly cut the few floors I've done with just enough "slop" for them to work out OK. I have been building hotrod and stock car chassis off & on since 1968 and I learn something new every time I do another one. Just goes to show that you're never too old to learn...

Brickman: The process is called "tabbing" in the business (boats primarily). What you do is lay your plywood in place, then lay up strips of fiberglass in an L shape , part of it on the plywood and the other part of the L on the body. You wet it out, then you lay another L shaped piece over the top of that one, with each sucessive one slightly wider than the last one, so that each one goes out a little further than the last one. The reason for this is so you don't create a hard, sharp place, where the glass can start to crack out. Each L is wider than the last one, if you can envision that. When I start the glassing I will take pictures to show this.

J: You probably put enough gap in those ones you did to be ok, it doesn't have to be a huge gap, just like a 1/4 inch or so. Yeah, I learn something all the time, and this forum has been a real learning experience, as we have some really talented folks on here, in a lot of areas. Wish I would have had a forum like this years ago.


Don

I kinda got a little late start today, but continued working on the shifter. I decided to go with the Craftsman wrench, what do you think of it???


Don

Just kidding !!!!!!!!!!!

No, actually, I am using the early Ford shift handle, and built some brackets out of 3 x 3 angle iron that I cut into a shape . I am going to use a spring loaded ball bearing as a detent, so that the shifter clicks into each gear. I still have some work to do on that, but about 3/4 of the shifter is done.

Here are some pictures, starting with the angle iron I cut, and then the pretty much laid out shifter. I could have just ordered a Lokar, or Gennie, but this was more satisfying, and I have about 20.00 in the whole thing so far. Used lots of scrap steel out of our scrap heap.

Thanks for looking.

Don

Heres one more shot.

CHEVYBOY:

Yeah, when I race it I'll use the 1/2 inch for quicker shifts.


Don

looks pretty good.. if is was me id use a 1/2" for that shorter throw

Harmon

So Don, you are just making your own floor? Will this be cheaper than just getting one from Speedway Motors you think? I never understood how to attach these things to a glass body but I am guessing through an angle iron shape on the body and set the floor on that or what? I am trying to invision what you guys are talking about here and about 5% of it makes sense to me and that is the part of the wood rubbing the glass. Remember I told you about the 4 door for sale? I am not sure if I am going to get that now because I cannot get the money in time and so I am going to start planning out a glass bodied car. I'm just worried about building a glass car from all the bad things I hear about them. If you can get some pics from this process then that would be great! If I got a T kit like yours (or maybe the roadster one) I would want to channel it and such so the pictures will definetely help.
I am going to go back and read most of this thread now to see all that I missed!

Ok thank you Don, I completely understand this now. How about using Fuzor instead of glass matt? We use Fuzor at the shop all the time and man that stuff is STRONG! I know a lot of people are using it now to weld panels together (or fuzor them together instead of weld)... Either way, I now know exactly what your saying. What size plywood should I use if I do this? Only thing I would worry about is rotting of the wood later but then again it won't be out in the rain much with no top. lol