S4 “gelcoat”

[Backmarker]

So the Sandi68S4 Elan. I’ve read many mature threads where folks were into some heated discussions regarding “gelcoat” on our cars. I’m only referring to my car.

Just offering a few images and aren’t I lucky this car was only repainted once.

The numbered one shows the telltale blue/grey over the GRP with primers/L06 then primer/red. The next shows GRP, then a filler, then the blue/grey layer.

So it appears, at least on this shell, that if the blue/grey is a “gelcoat” it was applied post-mold removal and the shell corrected for any layup imperfections prior to that application.

The third is a bonus, shows the sill being painted L06 then the correct black over.

[Grizzly]

Yeh, Caused lots of friction this one........

So when Lotus started making their own bodies they used a layer of resin rolled in the mold as a gel coat....... yes technically it would work as a gel coat but today it would need a thickening agent and to be semi-cured before the fiber layers are applied but they didn't due to time restraints (i believe most gel coats are sprayed into the mold to prevent bubbles if hand-laid now).

Beware, the Lotus 'Gel coat' is very thin and easy to break through into the fiber layers which isn't ideal.

If you compare another car like a Jenson that had a GRP body you will see exactly how much Lotus tried to put the process on a diet.

Just to add, the hi-build primer layer was the Blue/Grey colour unless of course, you have a Bourne body (they did have coloured Gel coat used)

[PaulH]

Yeh, Caused lots of friction this one........

Can't resist adding to this discussion. My Elan is a fairly late S2 (1966), so a Lotus produced body, and I'm convinced the first layer into the mould (call it gel coat or first resin layer) was a grey coloured resin. In the attached picture you can see the underside is grey, and I'm convinced it's not painted.

[Backmarker]

So file this in the same category as badge placement. Thanks for the images.

Jim

[Grizzly]

Yeh, Caused lots of friction this one........

Can't resist adding to this discussion. My Elan is a fairly late S2 (1966), so a Lotus produced body, and I'm convinced the first layer into the mould (call it gel coat or first resin layer) was a grey coloured resin. In the attached picture you can see the underside is grey, and I'm convinced it's not painted.

Body underside 7.jpg

wouldn't shock me........ from my experience the earlier cars were the best constructed and they got thinner/lighter with more brittle/drying out issues etc as you get later..... can you see where the sections were joined?? it's usually easy to tell the difference between a 'Gell coat' and high build, Gel coat is fused into the matt/resin layers so is next to impossible to get off without grinding it off, paint on the other hand will chip off with stones and will scratch off fairly easy with a coin or something blunt.

On my 71 2 seater that had never been painted (outside the factory) i had a grey floor that just had the wheel wells, front and rear valances painted bodycolour, the overspray had been allowed to drift over a grey primed floor. Strangely it looked very similar to yours where it's come off in the arches. Was you car Gold??

[dynodave]

In studying my S3 SE Coupe body in planning to do a rotisserie, I find this version did have gray gel coat. It was very thin on the belly/floor portion. The gel was put on with a paint brush as observed by the streaking. The top body mold had much thicker and solid coverage.

[Backmarker]

A cool “carchaeological” find, thank you for sharing, more evidence for the books.