Hardtop Project

[john4337]

A friend acquired an ERA and this top was on it. He didn’t want it, so I was able to get it, going to make a run at fitting it to my FFR Mk4. No info on the manufacturer and I’ll have to come up with mounting on my own. Any thoughts or ideas are welcome.

John

[john4337]

Here it is sitting on my Mk4.

it looks like the attachments they were using behind the doors pulled in as well as down and the top is narrow there, will have to pull it out. There’s a big Gurney bump that I’ll take out as well.

[mrmustang]

You are going to have to build up the lower rear of the top to physically mate/mold itself to your car. Can't cut and lower it, or you'll put too much stress on the front windshield mount and crack your windshield in the process.

Bill S.

[john4337]

I've pulled the windows and weatherstrip off. My goal is to mount the top in such a way that I can go back to my soft top, which means using the soft top points. I cobbled together this as a proof of concept but it looks like it will work. A buddy who is a machinist came over and took some measurements to make some nice brackets to replace these. Next step is to cut off the lower part of the top and place spacers to get it to line up with the body. I'm shooting for about a 3/8 inch gap to allow room for weatherstrip. Thoughts or ideas are always welcome.

[john4337]

Well, I took the plunge and took a cut off wheel to it. The contour looks pretty good on the drivers side, the passenger side not so much. The top had a ridge detail around the lower edge that I elected to take out because I didn't think I could make it look right after adding material to fill the gap. This also moved the lower edge of the top forward a bit, giving me more clearance when opening the trunk.

[CowtownCobra]

Nice looking hardtop. I like a top, never give it up now

[DanEC]

Nice thing about fiberglass is that you can do just about anything with it that you want. But, you’re going to need to figure out the source of why it wants to sit higher on one side than the other or the view from the rear is never going to look right. I suppose most of that is from where the front is resting on the windshield header. I doubt your windshield is off that much ( but might check the angle from side to side). That leaves the possibility the top is twisted/ warped across the top area. I that appears to be the case, it can probably be worked out with heat and strapping down to a temporary support. It will be difficult as applying heat on that large an area is tricky. It might just have to be strapped down to a jig and placed out in the summer sun for a couple months to let it relax. I reshaped a trunk lid by strapping it down to add more bow to it and the played a heat gun back and forth over the surface to relax it and then let it sit a couple of weeks. It’s been fine for 10 years. But too much heat from a heat gun can literally soften fiberglass to a very soft plastic stage - have to be careful.

I’m not saying this is definitely the problem or solution - just my best guess from your pictures.

[john4337]

I agree. It was pulled way in at the bottom corners by the doors when I got it. I spread it for a few days and it got much better. I've cut the bottom sections up some and they lay much better. Might have been a warp, or the car the mold was splashed off of was a bit different. Who knows....I learned a long time ago to stay away from my car with a tape measure, it'll drive you nuts.

Originally Posted by DanEC

Nice thing about fiberglass is that you can do just about anything with it that you want. But, you’re going to need to figure out the source of why it wants to sit higher on one side than the other or the view from the rear is never going to look right. I suppose most of that is from where the front is resting on the windshield header. I doubt your windshield is off that much ( but might check the angle from side to side). That leaves the possibility the top is twisted/ warped across the top area. I that appears to be the case, it can probably be worked out with heat and strapping down to a temporary support. It will be difficult as applying heat on that large an area is tricky. It might just have to be strapped down to a jig and placed out in the summer sun for a couple months to let it relax. I reshaped a trunk lid by strapping it down to add more bow to it and the played a heat gun back and forth over the surface to relax it and then let it sit a couple of weeks. It’s been fine for 10 years. But too much heat from a heat gun can literally soften fiberglass to a very soft plastic stage - have to be careful.

I’m not saying this is definitely the problem or solution - just my best guess from your pictures.

[john4337]

Got some more work in on the top. Getting closer.

[CowtownCobra]

Looks good. Interested to see how it turns out

[DanEC]

That does seem a lot closer now, at least if it’s sitting square on the windshield header. Now to just break out the grinder, fiberglass materials and get itchy.

[john4337]

I spent yesterday fine tuning the top alignment at the beltline and then cleaned it up and stated glass work today. A bit challenging as I was often working on vertical surfaces, but I got there. I'll let it set up good overnight and see where I need to add more.

[john4337]

Here are some more photos.

[john4337]

Last ones for today.

[john4337]

Well, I've pulled the frankenstraps off and done an initial rough sanding. Then I put the gasket that came on the car back on and set it in place. For the hardtop guys out there, what type/size gaskets are you using and what is the gap between the top and the body?

Any thoughts are welcome. Ohh, ignore the gasket placement in the next to last shot, I have a glob of fiberglass on the lip that isn't letting the gasket sit correctly.

John

[mr bruce]

get yourself a cheepo angle grinder from Harbor Freight and some 24 grit wheels and cut thu the gell coat and taper the joint, feather it out, no hard corners. you want it as rough as possible for the glass to adhere to the base material. you are now dealing with a mechanical bond since you're dealing wth old cured glass and new wet resin. take the top off the car and do it outside, one slip and you'll be crying

[john4337]

Originally Posted by mr bruce

get yourself a cheepo angle grinder from Harbor Freight and some 24 grit wheels and cut thu the gell coat and taper the joint, feather it out, no hard corners. you want it as rough as possible for the glass to adhere to the base material. you are now dealing with a mechanical bond since you're dealing wth old cured glass and new wet resin. take the top off the car and do it outside, one slip and you'll be crying

Thank you!!

[DanEC]

Mr. Bruce knows his stuff. Need to bevel grind or dish grind the areas deep enough, front and back, to lay in about 4 layers min., of mat and resin, rolling each layer out to compress it and remove excess resin. Cut each strip a little wider than the last so that it fills up the dished area in layers with the last slightly overlapping the original, full thickness fiberglass right under the gel coat. Then grind and sand to contour, fill any minor areas or pinholes with filler, and prime with a couple coats of high build polyester filler like SlickSand for final blocking down. That’s the only way to fully hide the splice joints in the finished paint.

[john4337]

Here are some shots without the gasket. I'm thinking I may need to go thinner.

[john4337]

Here are some shots without the gasket. I'm thinking I may need to go thinner.