Ricks MantaProject.com build log

[Blueovalz]

I had a similar problem with a previous car. Solution was to bond 1/4" ID fiber tubes (you could use larger if needed), one on each side, about 1" long each, into the fiberglass panel, and sanded flush with the top side surface. I slipped vacuum hose on the underside ends. Rain (or wash) water would drain down these small holes and out the vacuum tubing directed out under the car. The holes were barely noticeable, and served the purpose well. I used fiber tubes from McMaster.com because they would bond well with the fiberglass. I would hate to see you take the rear lip off.

[Rick]

When I first got the car it had holes drilled in the trunk that just drained out through the bodywork since there was nothing back there anyway to hurt. I filled them in when I had the caddy 500 in and repainted the car. This time around I plan on putting a storage area in the back so that whole area will open up and I am wanting to keep it dry. I can make a wing that maintains the lines of the car and works without the problems the design has now. I am never going to take the car on the track so it isn't going to matter about changing the high speed handling. The electric drive system will have a top speed of around 90-100 anyway when it gets installed. I made a foam wing yesterday and it fits the car well. I have the post up on my site but it wasn't behaving last night to let me post it here. I will get it up here in a few minutes.

I will spend a few more days playing with the design and see if I can come up with something nice before I cut the spoiler off the trunk lid either way so other than wasting time I don't figure it is going to hurt anything if it doesn't work out.

[Rick]

March 25, 2016

I started trying to build a wing for the trunk lid. I am using foam and shaping it to get the look I am after. Then I will make it out of fiberglass and mount it to the car. It will fix one of the big problems with the trunk and hopefully look nicer.

I found a few sheets of foam insulation. and cut some strips out and glued them together to get the thickness I needed. After cutting them to shape with an electric knife and getting the basic outline of what I was after I taped it down and fit it to the car.



Then I used a random orbit sander to give it roughly the profile I was after. I copied the shape from a spoiler I had laying around and started working it into that basic profile. It was pretty easy to shape and if it got messed up I could always glue more material on and start sanding again.



Once I had the shape figured out and it looked nice and even I started putting the final shape to it. I am making it the size I plan on having the finished spoiler and making sure it looks right on the car. I have it really close to where I want it now, just a bit more smoothing and shaping and it will be perfect. Once I have it where I want it I will make it out of fiberglass.



For reference here is what it looks like now. That dirty spot is always there, any time it rains that is where the water collects on the body. If I am going to drive this car all year round it is going to get wet and the paint won’t last long with it always holding water. With that lip cut off and the wing in place it won’t be a problem anymore and it should look nice as well as give me a place for a third brake light.

[Rick]

After spending a few days measuring and trying to find the best square on the trunk lid I managed to get a line that looked pretty good. So today it was time to cut the trunk lid and get started shaping it to be set up the way I am wanting. It was pretty quick to cut, I just used a jigsaw and followed my line around the whole thing.

From there I glued in some foam to fill in the area. I did some rough shaping and set the wing on top to see how it looked.



I was not happy with how the foam shaped and it was not easy to shape in the tight space so I pulled the center piece out and tried again with cardboard. It held the curve much better and is a lot closer to what I am after.



It is just taped in place and is not tight to the body but it is more or less where I want it to be. I will have to round the edge over but that would be easier once I get a layer of fiberglass on the cardboard. First thing I need to do before I fiberglass it all solid again is to smooth up the lower cut line. It is going to be where the trunk lid closes so there is no point in joining it back together just to cut it back apart as soon as it is done. I will get that line evened out and smooth then tape it up so the top part doesn’t bond to it. That will make cutting the rest of top free much easier.

[Rick]

Overall I think it looks pretty good and it will make the car look better by breaking up some of the huge flat areas on the car. The wing is still slightly oversized but once I get the trunk lid fiber glassed back together I will do the final shaping on it and then reduce it 1/8 inch and fiberglass over it. I am not sure if it is worth using a bit of acetone or something and removing the foam out from inside the wing or just leave it there after it is done. I am thinking for now to just leave it in there.

[Rick]

I didn’t get much time today to work on the car but I managed to get a few things done. First thing was level out the new trunk lid lip. I started by clamping a pvc pipe to the back to hold the slight curve I need. I tried measuring out a straight line for the trunk lid since it would be easier to make but the rear body is not made square enough and no matter what it doesn’t look even. A slight curve keeps it from being noticeable.


Once it was straight I covered it with packing tape to keep the trunk lid from sticking to it. I cut a bevel into the top so the new material will have a better bond. After that I put the filler back in place and laid a layer of fiberglass over it. The shape is only approximately right but it is such a large area it is hard to get everything right in one pass. My plan is to let it cure for a few days while I am at work then when I get back on it I can remove the support from underneath it and cut and form that single layer a bit better. Once it is close to where I want I will build it up and join it into the old body panels good. That should give me enough thickness to get it nice and flat and be thick enough to mount a trunk latch in it without breaking over time.

[Blueovalz]

FYI, floral foam (dense soft stuff for flower arrangements) works great for fiberglassing pieces. Sands extremely well, does not react to resin, and can be easily removed after the glass has kicked. I use it for every piece that requires 3-D sculpturing (scoops, doors, etc.

For example:





Installed in the nose:

[Rick]

It has been cold and terrible weather for fiberglass work so not much has been done the last week or so. But the weather is looking better now so it is time to get the work on the trunk lid going again.

I have 5 layers of chopped fiberglass over the first mesh layer now. It is starting to look good and won’t be long before I have it thick enough to work. I figure another 3 layers of chopped fiberglass and maybe a layer of mesh on top to make it look nice should be about right. I need to build up the thickness of the back edge a lot more. I will probably put about 6 layers on it. Then after getting the top cut off I can go back under it and put several layers and get it to about 1/3 inch thick. It should hold up good and not warp or do anything for a long time if I make it that thick. I will let this part set up and dry for a few days and maybe by Wednesday I can get the last few layers done.

[Rick]

Still working on the trunk lid. I have it thick enough now to be nice and strong. It is pretty close to level now and you can finally start to see what it is going to look like. I haven’t had much time to mess with the car but that just gave the fiberglass plenty of time to set up I guess. I put the last few layers on it today to get it up to full thickness. It is now slightly thicker than the stock fiberglass so it should hold up to being used as the edge of a trunk lid without much problem.



I still need to build up the back it is kind of thin and will need built up pretty good. I will get it built up then sand the whole thing down nice and level. I will probably go ahead and try out putting gel coat on and see how it works before I cut the lid free. Once the lid is free and reinforced on the bottom with some metal bracing I will start putting the finishing touches on the wing and make it in fiberglass.

[Rick]

I have enough fiberglass on the new section of trunk lid to make it good and strong. It just needed some sanding and it is about done.



The fiberglass is in the right shape and angle. It will need a bit more finish sanding and a good coating of gel coat to finish it but for now it is good. I will do the finish work on it when I do the rest of the bodywork. Next up is to cut the top off the trunk lid and get that part working like I want it to. The hard part of modifying the body on this car is nothing on it is really square or the same from one side to the other. Making a template to cut one side and then flipping it over to cut the other side wont match at all. The only thing that can will look right is to just line it up with what looks right. The easiest way I have found to make a complex curve that flows well along the lines is to use PVC water pipe.I taped it in place along both sides of the trunk and adjusted it to make it look balanced and as even as I could get it.



After it was taped down and as even looking as I could get it I used a marker and put a line on the body to cut. I didn’t have enough blades for my saw to get the job done so That seemed like a good place to stop for the day. I plan on making the cuts down the top of the body then lifting the car up and cutting through the fender wells and anything else that needs cut to get the lid free. I can then reinforce the lid and the body to hopefully make it all work out right.