Seeking input on body sealers

I am in the process of installing a Monocoque covered headlight system in my 69. Chuck provides a nice replacement kit which includes new diaphragms. I have discovered that the original (and the replacement) diaphragms don’t fit snu

gly against the bonnet and fenders even with the little flanges that are attached to it. I obviously have to fill in some seams and even holes. 3M 4200 sealant was suggested but this seems to be difficult and expensive to find. I was wondering if anyone has found a nice sealer that holds well but that remains flexible. Auto parts stores sell a variety of black silicone based sealers and that seems like an obvious choice but I might be missing something. Any thoughts?
I have attached a picture that shows the old “goop” that was used to plug the gaps around the diaphragm.

DM me on the experience with the MM enclosed kit. I keep waffling on whether to do that to my '69.

Looks like it’s sealed with road grime!

Anything by 3M or Sikka will work well.

I am bringing a tube of Sikaflex to the painter. I think-hope- that this is better in the tragic event that you ever have to pull it out and re do it.

it’s on Amazon, cheap and fast delivery

I ran into another problem as I was assembling the diaphragm parts. The connector block disintegrated an I bought a new one BUT I realized that a number of black wires (ground ?) were not connected to the block although one was. In the attached photo, you can see three black wires that are not connected and one (with grey paint on it) that is. It seems to me that I should just connect all of them together but I thought I would ask for advice.

It looks like the black wires that are not connected are all ground wires from lamps. All lamps had a direct ground connection. Generally lamps had a ground connection like:

which a black wire would plug into. The other end of the black wire would go to a ground connection like:

which will be somewhere in the area. Looking at your picture there should be a black wire going from the opposite side of the black wire in the connector to a ground connection. This is the wire that grounds the bonnet to the frame.

Richard Liggitt

Hello Bill,
And all Sikaflex products aren’t made equal.

The best of their range for the purpose of bonding E Type Bonnet components, in my experience, is SikaPower-4720, followed by Sikaflex-252. Cheap is not always cheap, when you have to pull the bonnet to pieces and do it again.



1 Like

Most adhesives have a shelf life. With some “glues” this shelf life is very, very critical. A possible explanation for cheap tubes from some sources.

Larry and Bill.

the 221 I bought has 6 mos dating.

I always thought the point of 221 was it will do the job and, if you have to yank it off, you actually can. I thought the bolts held the bonnet together and the Sikkaflex was just added protection and stopping squeaking?

Am I wrong?

Hello Bill,
The various metal brackets that are glued to the bonnet proper are to stay there and should be glued on as permanently as possible. I tried 221 quite a few years ago and found it to be poor performing for the purpose relating to E Type bonnet assembly. Even at four, or five time the cost of the best bonding material available, its small change in the whole scheme of things when restoring an E Type Jaguar. Accordingly, I would opt for the best product I can get my hands on. SikaPower-4720 is the recommended product from the Sika range for replacing glue on panels in the Auto Industry and 3M have a similar product. I would use only these products.