Lift-the-dot stud question

[DougD]

I am wondering what everyone is using for the Lift-the-Dot studs to attach a top and tonneau to their Cobra.
There seem to be two types for this use, a machine screw version, and a self-tapping screw version.
I'd like to use a machine screw version with a washer and nut.
Is there one that is long enough to use on my fibreglas-bodied CSX4000 Cobra?
I'm not sure that a self-tapping one would be strong enough over the long run.
Your thoughts?

[Jerry Clayton]

the self tapping versions work for a long time on boats and they are fiberglass

[ERA 778]

ERA cars come standard with the self-tapping type. I also considered the nut and washer route, but after looking at the ones provided and considering that there were some spots I wouldn't have access for the nuts, I decided to stay with the ones ERA provided. I think they're strong enough and should hold up very well.

Hal

[Tom Cimino]

The self tapping type worked well for me too. A couple of hints. Find a sheet metal screw with the same threads to start the threads into the fiberglass. Work the screw back and forth gently to cut the threads. This lessens the chance of snapping off one of your studs. Also install the studs with a thin nylon washer to minimize paint damage. This method worked for me. They have held up for 15 years now.

[mickmate]

Hey Doug, I used the machine screw type then tapped the hole. After tapping the holes into the glass I still had room for a nyloc on the bottom. A couple of them weren't quite long enough to get as far as the nylon but it worked out fine as they have more thread thru the body. You will have to remove your rear inner fenders panels that are pop riveted in to reach a few around the sides. While you're in there might as well position and attach some roof bow ferrules if you don't have them.

[DougD]

Hi Nick
So did you use the 3/8 or the 5/8 length studs? I'm thinking that the 5/8 would be long enough to extend through the body and still leave enough threads to put a nut on. Although it seems others have used the self-tapping style with no issues.

Thanks for the reminder on the ferrules. I had Finish Line in Vegas fab up a couple of them several years ago. I wonder which box they're in....

On a side note, thanks for chasing down the deal on the Billboards. When I'm back home in May, one of the first things I'm gonna do is get them mounted up on my set of FIAs. Can't wait to see how my Cobra looks with those tires on my favorite wheels!

[cobrakiwi]

I use the 5/8 long studs and a stainless fender washer, with nyloc nut to spread the load on fiberglass. In some places the 3/8 studs are just a bit short.

[DougD]

Anyone have 20 or so of the 5/8 machine screw thread versions lying around? I hate to buy a box of 100.

[CHANMADD]

I have had the self tappers for 20+ years .....no problems......just reminder too ..go slow like said above but also use a little engine oil to lube the process and clean once the threads are right in the glass

[Rick Parker]

Doug:

Go to a boat supply shop or someone that does marine upholstery, they will have open box stock.

[mdross1]

Originally Posted by Tom Cimino

The self tapping type worked well for me too. A couple of hints. Find a sheet metal screw with the same threads to start the threads into the fiberglass. Work the screw back and forth gently to cut the threads. This lessens the chance of snapping off one of your studs. Also install the studs with a thin nylon washer to minimize paint damage. This method worked for me. They have held up for 15 years now.

This is exactly what we did almost 19 yrs ago,we use the top a lot otherwise the tonneau is on when I take the car to work.

[Rick Parker]

Mark out the pattern. The self threading and machine screw items have different Root diameters and will require different hole sizes. Use the self tapping types around the door openings where the glass is most likely the thickest. The idea of a thin large diameter washer is well advised. Between the Liftadots and the body use a thin fibre washer. 16 studs in the pattern. Most use the 3/8 length.

[FIA-ERA]

With out a doubt the most stressful part of my Cobra's assembly!!! I drilled the holes out, tapped the screws in, sprayed the primer, tapped the holes out again, sprayed the paint, tapped the holes out again, ran a tapered tap through, then finally installed. Make SURE you use a "Fiber" washer underneath as it will help seal up the last little bit. Be careful too around support tubes. If it hits anything else your screwed, literally. Of course this is on a fiberglass car. I DID NOT like this part of the build. Everyone advice here is spot on too.

Regards, Matt

[DougD]

Great comments, guys. Thanks.
I am sweating this step. I think it is an important detail to achieve the original look I am hoping for.
A tonneau is definitely part of the plan. I'll install all the appropriate pieces to mount the top, but I'm not sure it'll ever be used.
I hadn't considered a fiber washer between the fitting and paint.

[Rick Parker]

The washer gives the paint a pliable suface between it and the Stainless metal on the Liftadot. Prevent the paint crom potentially cracking as the post is tightend down.