Tonneau Cover Questions

DaytonaTim · Post by **DaytonaTim** » Wed Jan 11, 2006 1:52 pm

I want to thank everyone, once again, for the help ya'll gave me on my fog light question. Now, I have another one.

I am starting a tight budget "restoration" on our Mclaren and I have a question about the tonneau cover. My problem is, I do not have one. My car came with a home made tonneau that extended all the way foreward, to just behind the seats, thus covering the storage bins in the back.

I would like to try and make a tonneau that looks like the original but I have no idea what an original looks like.

After studying my car and pictures on this site I have come up with the following:

1 It appears the tonneau cover must have a rigid backing. this is probably about 1/4 inch thick. Is this thickness constant from front to back?

2 It appears to be covered in either leather or nauglehyde (sp??). Which material is used?

3 The front of the tonneau extends downward to meet up with the carpeted vertical section behind the storage bins. Should this extension lap over the front of the vertical section some, or does it just butt to the top of it?

4 The outer edge of the tonneau (back and sides) appears to extend downward to meet up with the finished painted horizontal section of the hatch that covers the top when it is down. Is this so?

5 Is the tonneau cover padded. If it is padded, about how thick is the padding? Does it have a slight arch accross it's horizontal surface? if so, about how much of an arch?

I know these questions are kind of tedious to read but I have found that not many people take good closeup pictures of the tonneau cover and I have never seen another Mclaren before. So I am kind of stuck

Any help or advice you can offer would be much appreciated.

And Yes, I know Hank sells them for $314, but like I said I am on a tight budget. Legaly fighting with an ex-wife that has been diagnosed with a narcissistic, cluster B personnality disorder does tend to drain ones finances a bit.

I did win, but the lawyers got the restoration money.

Sandy · Post by **Sandy** » Wed Jan 11, 2006 3:33 pm

I understand your situation, and I do empathize with you & also admire your spirit in wanting to make one. However, IMO it would be totally impossibleto make one that is any good. Why? Firstly, the tonneau is made of a hard material. I am not sure if it's aluminum or fiberglass. I think fiberglass ~ whatever, it is precission cut to fit many tollerances and bends and curves, as in whereit meets the side of the car and the dip-cut, as well as the curvature around the back, where it meets the trunk. There was recently one on e-bay being parted out. Too bad you missed that one, as it was also black in color. Keep watching e-bay for other McLaren wrecks being parted out.

DaytonaTim · Post by **DaytonaTim** » Wed Jan 11, 2006 6:03 pm

LOL..... Sandy........ take a quick look at my album.......I live for fabrication challenges....... and they will probably be the death of me

plumkrazy · Post by **plumkrazy** » Wed Jan 11, 2006 7:24 pm

That was some job you did with that body from start to the end.
So to understand, you made the body then laid fiberglass over the whole thing for a body? how did you get the shell off the mold with out breaking it?

mustang marty · Post by **mustang marty** » Wed Jan 11, 2006 7:43 pm

Are you talking about the interior matching part that is attached to the tonneau cover lid or the whole lid itself?

DaytonaTim · Post by **DaytonaTim** » Wed Jan 11, 2006 7:48 pm

mustang marty wrote:Are you talking about the interior matching part that is attached to the tonneau cover lid or the whole lid itself?

I am talking about the part that matches the interior. The part that looks like it is made of leather or vinyl.

Not the whole entire lid, just the upholstered portion

DaytonaTim · Post by **DaytonaTim** » Wed Jan 11, 2006 7:59 pm

plumkrazy wrote:That was some job you did with that body from start to the end.
So to understand, you made the body then laid fiberglass over the whole thing for a body? how did you get the shell off the mold with out breaking it?

The black "body" that looks like it is mounted to a pedistal is actualy called a plug (a positive mold). It is a fake car, a sculpture made of wood, foam, spackeling compound, body putty, and just a little bit of fiberglass. The fiberglass I layed over it was layed up in multiple flanged sections, allowing me to separate them from the "plug".

You remove these flanged sections and bolt them together to form a negative mold. You then lay fiberglass up inside the mold, then unbolt the molds and remove them from newly layed fiberglass body.

So first you make a positive mold....... the plug
You then make a negative mold.......
Finally you make a positive piece...... the actual car part

It is time consuming but when you are done you still have the negative mold to layup aditional bodies........

Like I said..... I like a fabrication challenge......

dahberg · Post by **dahberg** » Wed Jan 11, 2006 8:39 pm

1 It appears the tonneau cover must have a rigid backing. this is probably about 1/4 inch thick. Is this thickness constant from front to back?

* Yes, perhaps 3/16, but no more than 1/4 inch. *

2 It appears to be covered in either leather or nauglehyde (sp??). Which material is used?

* Vinyl - I can not spell naugahide either

*

3 The front of the tonneau extends downward to meet up with the carpeted vertical section behind the storage bins. Should this extension lap over the front of the vertical section some, or does it just butt to the top of it?

* Butt up to the top, even with lip of back edge of tub area - it does not overlap in front! *

4 The outer edge of the tonneau (back and sides) appears to extend downward to meet up with the finished painted horizontal section of the hatch that covers the top when it is down. Is this so?

* Yes - this does taper off some what from the 1/4 inch thickness (maybe to 1/8 inch to accommodate material glued to inside edge) pointed out in question number 1, but not to an extreme thin edge. *

5 Is the tonneau cover padded. If it is padded, about how thick is the padding? Does it have a slight arch accross it's horizontal surface? if so, about how much of an arch?

* I am speaking from first hand experiences with a 1985 cover and there was not any padding under the material. The original cover was a very hard black piece of plastic material. This was flat, no bow appearent. I am not an expert by any means and would not know if any fiberglass was used in the original. I purchased a replacement from Hank due to large cracks that developed in the original that were providing an uneven surface under the attached material (bumps and ridges were appearing on the flat surface). Hanks repacement was made up of fiberglass. You should be able to create your own mold without any problems judging from your photo album. *

DaytonaTim · Post by **DaytonaTim** » Thu Jan 12, 2006 1:11 pm

Hey, thanks a lot Scott.

I have been thinking about it and I think I will try and shape the piece out of sheet metal and use plywood inderneath for the spacer. I may not take the tonneau all the way down on the inside, instead I may try using a teak filler strip. This will match the other teak strips on the dash and console.

It may not be original but it will be a lot easier to fab. Besides, anything is better than that monstrosity that was on it to begin with. What do you guys think?

I will take some pictures during the process and try and post them in the future.

Besides, after the lawyers quit sending me their bills, I can always tear it out and replace it with one that I purchase from hank in the future........

Thanks again Scott.