So, at some point I need to down this thing and get the paint & body work done, but at the moment I'm just enjoying driving it too much. I'm not equipped or skilled enough to do some of the things it needs, so I'm probably going to need some professional help with it anyway. In the meantime I wanted to close up the open top, in the summertime the sun beating down on you while driving in traffic can be brutal, that's the biggest concern. But in addition, it would be nice to cut down on some of the wind buffeting and noise too. That would also make it more bearable on cold night drives too. But I wanted to be able to remove the top, because there are times when driving with the top open is really nice, particularly on moon lit warm summer nights. Probably the easiest way to do this is with a snap on canvas top, which I've given a lot of consideration to, and have collected a lot of pictures of rods with snap on canvas tops, but I'm not thrilled with the look of the snaps, or drilling the top to install the snaps. So I came up with a low cost idea using thin plywood and wooden clamps to hold the top in place, which would make it easily removable with no tools required, and I'm pretty satisfied, if not 100%, with how it came out. At this time, it's a temporary fix, so we can drive the rod in more comfort this summer. Whether it stays permanent remains to be seen. I'll start posting pics in following posts.
I started by taping a couple of pieces of poster board together to make a pattern: Then transferred the pattern to wood and cut it out with a jig saw. Then I fitted a couple of bars to the plywood that slip in between the front header board in the cab and the steel cab top, taking advantage of the fact that some previous owner for some reason I don't understand decided to shave the header board down. This was critical to making this all work. The turnbuckles shown above were added later, but I'm getting ahead of myself, so I'll get back to those later. So here is the initial fitment of the rough board to the top, still got a long way to go, but this is the start. This was going on while I was waiting for my radiator to be repaired. It gave me something to do.
For the clamps I just cut a 1 x 2 oak board into 3" sections, and then cut a 1" wooden dowel for spacers, and attached them to the top with ss screws, flat washers and nylock nuts. 2 clamps per side and 2 along the back. Here is the top with the clamps installed, pulling the top down tight to the cab. This is s till very rough, at this point I was still in the "proof of concept" stage. I really didn't know if this was going to work at all, it was just an idea that I was fleshing out to see how it went. Here's an inside look showing the clamps. This was encouraging, but I had a problem I needed to deal with before going any further. When pulling the top down and clamping it to the cab, it caused the center of the front edge to pop up, this simply won't do. I got to get the entire front edge pulled down tight. Imagine the wind catching this at speed and ripping the entire top up and off while driving down the freeway at 80mph! So I addressed this by mounting a steel bar to the inside of the plywood top, then using turn buckles to hook to the rear view mirror bracket, and pull the top down. Actually, when installing the top I don't really use the turn buckles to pull it down; when installing the top the front edge follows the roof line very nicely, all I do is connect the turnbuckles to the mirror bracket and tighten them finger tight, then when I pull the top down along the sides and back the front edge stays tight to the cab. And now the top stays nice and tight and follows the roof line nicely. So at this point, I was satisfied enough with the proof of concept, that the idea worked; so next I pulled the top back off and straightened the lines, rounded the corners, and sanded it down smooth, ready to finish it after I did some test driving with it.
Well, the test drive revealed something I wasn't expecting. The top did the job I was hoping for, mainly it blocked the sun making for a much cooler ride in the summer heat. And it blocked out the wind entering from the top, and it diminished a lot of wind noise, and this was all good. But it introduced a lot of additional noise, which surprised me. The top itself doesn't add noise, but it reflected all the other noise in the cab, any rattle from the doors and the exhaust noise all got reflected back down into the cab. Crap! I installed baffles into the lakes pipes to quiet down the exhaust, and now it was back again, with a vengeance. I originally planned on just leaving the wood finish on the inside of the cab, maybe just applying some linseed oil & turpentine. But now I was looking at adding some material to the inside to quell some of the sound waves that were bouncing off the wood and crashing back down on my ears. And as I thought about it I realized that if the wood wasn't there, then it couldn't bounce the sound waves back at me. Hmmmm, so what if I open it up? I thought about this for awhile, and then I did what any self respecting hot rodder would do, I filled it with holes. Here's what I started with: And here it is with the holes:
Well, now that I have the top full of holes, the next step is to line it with something. I decided to give it somewhat of a stock appearance from the inside. So I went with some cotton batting and good ol' chicken wire. The staples in the middle are hidden by the wooden bows in the roof. For the top side I went with some poly batting and black vinyl material. 1 yard of material was enough to cover it. And here it is installed on the truck: Another angle:
Just a short drive around the neighborhood didn't show any noise problems, so I think the Swiss Cheese treatment did the trick on getting rid of the sound wave reflection problem, but I may need more time in the seat to be sure. In any case, the top definitely does help with the sun and wind issues, and it installs and comes off in just a couple of minutes, but fits snug and secure with no lifting problems that I have noticed at this point. I'm not sure how that vinyl is going to work out, I may need to glue it down in addition to staples, we'll see about that. Here's a few more shots to close this out:
This evening we took it out for about a 40 mile ride, half of that being on the freeway, where we got it up to just under 80 mph. On the way back we jumped off the fwy and took the road thru the canyon back to town, a very nice drive. At speed the top itself rides very nice, no movement at all. But there was some movement or buffeting of the cotton batting on the inside of the cab. I reached up with my hand and felt the outside vinyl, and I think there may have been some billowing going on, can't really tell from feeling it, I need to get somebody to drive along side of me to watch it for me, maybe even take some video so I can see it. I'm going to add some weather stripping in some strategic positions that may help reduce some of the wind buffeting of the cotton batting, and maybe reduce any billowing that might be going on. But the comfort inside the cab is much nicer. This will really help for taking longer drives, and should reduce fatigue at the end of a full day. I'm pretty happy with it so far.
maybe sew/glue some vinyl to the bottom side? nice job, i never thought of drilling the plywood to get it to form. i have always cut shallow slices
I'm thinking that the material will bellow up. A stock type top raises up somewhat when rolling down the road. In your case you could glue it all down. But then the holes will show.
I have noticed that convertibles always run better with the top down. There are all kinds of imperfections that fade away with wind in your hair.
Originally was the old vinyl top that came on the car in 1930. That disappeared long before I ever saw it, leaving just the wooden bows across the top. In case you're not familiar, these old A's did not have a full top, there was always an opening in them. There are wooden bows, oak I believe, that span across the opening, which was covered with chicken wire, then cotton batting on top of that, and then the vinyl was stretched across all of that. Every Model A closed car was built like that. If you look from the inside at an original A or a refurbished one you can see the chicken wire and cotton batting. That was the inspiration for doing mine like that. Otherwise some foam egg carton sound insulation would've done a better job. Here's a view of the roof without the insert.
Actually, I drilled it to control noise by eliminating the hard reflective surface. But it did make it more flexible. I went with round holes instead of square or triangular so as to not have any corners that could lead to cracking. Seemed like it would be stronger, maybe not.
The Jalopy Journal
