S1 body to frame bonding

[314159td]

I have a question particularly for those who have removed their S1 frame and/or have a good idea of how that was designed. 
I'm taking care of various fiberglass cracks and surface rust and have a lot of the body to frame edge bonds separating. It seems like the paint pulls away, rather than the polyester binder failing. Are these types of joints structural on the S1 Europa, or intended more to smooth out the transition and seal things up?

I've been cutting them off with a Dremel, with the intent of sanding the frame to bare metal and then bonding in more glass, but is that actually necessary? There seems to be a mix of bonding and fasteners used to hold the body to chassis, with the obviously structural bonds being in larger, flat areas. On the "floorboards" these edges seem more structural?, especially to the metal plate under the pedals.

Red is areas I've cut, green in the remaining glass pulling away. Weird green goo is Eastwood inside frame coating

[bjthomp]

Regarding your first question, the fiberglass is not structural; it is intended to smooth out the transition and smooth things out. I feel it is worth the effort to remove them, sand, and replace. Concerning the glassed portion of the floorboards, they help add rigidity to the floor by attaching it to the metal plate extending rearward from the frame tee. The frame appears to be fairly rusted which, should undergo extensive scrutiny to avoid future problems.

[SwiftDB4]

I would also be most concerned with the chassis rust. At the least removal of the chassis and sandblasting or chemical rust removal to evaluate strenght and safety.

[My S1]

I will confirm what SwiftDB4 and bjthomp have stated.  The fiberglass matt/polyester resin strips are simply to close things up and protect from water/moisture intrusion.  A small degree of structural rigidity may have been gained by the lap joints. In the case of my S1 the front of the T in the nose was solid but the interior floor board to tunnel strips were loose and there was surface rust on the steel back bone.  I removed the flimsy fiberglass strips, cleaned up the metal then laminated new fiberglass cloth/epoxy resin strips to create robust lap joints.  I followed up with strips of matt/epoxy to simulate the factory's half assed lap joints.

I am continually flabbergasted by the shoddy lay up work done by the Hethel boys.  The engineering, styling and sculpting of the prototype was first rate but the factory dropped the ball repeatedly during the production run.

I struggle with whether to live with the original sloppy work or rework things to make them stronger and aesthetically cleaner.  I don't want to be accused of "over restoring".  A real frustration.

[314159td]

The rust definitely looks quite bad, I lowballed hard when buying this car because of that (and the visible delamination).
I had a few of the ex-midwest and GM production guys from work take a look with the fancy borescope, and we're all pretty confident that the chassis doesn't need to be pulled, but another 5 years of improper storage and it would. I took at look at other removed frames and none of the common areas have anything significant on this one. Originally imported to Texas, then moved to New Mexico around 73 so that probably helped.
The front face pictured there is by far the worst area (makes sense, any rain would blow directly onto it), and around the master cylinder is a bit weak, so it's getting a large doubler plate that also covers the nasty steering column hole. New MC from R.Dent barely doesn't fit the hole so that'll be opened up slightly too.

Anyway, just stopped by WestMarine and picked up more epoxy and thickener to hit those vertical surfaces. The hesitation to over-restore is very real, but somebody already glassed a S2 front end onto this thing so I think I'm in the clear 

I didn't think about doing cloth and then mat over it, great idea. I was going to leave the interior largely unfinished for a while. A lot of the mat stuff isn't meant for epoxy, as only polyesther can dissolve the weak binder, but apparently it's still mostly okay? Nice article here: https://www.epoxyworks.com/index.php/chopped-strand-mat-and-epoxy/

[314159td]

Glassed up the lower seam, getting a feel for the filler so I can do the vertical ones without as much drippage.
Doubler plate seems like it should work out well, I think I'm going to rivet it into place and then glass over on the right side. Can't see any potential problems with that. Might even epoxy the plate to the frame after some prep work, just to keep rust from accumulating in any little gaps.

[lotusfanatic]

I will confirm what SwiftDB4 and bjthomp have stated.  The fiberglass matt/polyester resin strips are simply to close things up and protect from water/moisture intrusion.  A small degree of structural rigidity may have been gained by the lap joints. In the case of my S1 the front of the T in the nose was solid but the interior floor board to tunnel strips were loose and there was surface rust on the steel back bone.  I removed the flimsy fiberglass strips, cleaned up the metal then laminated new fiberglass cloth/epoxy resin strips to create robust lap joints.  I followed up with strips of matt/epoxy to simulate the factory's half assed lap joints.

I am continually flabbergasted by the shoddy lay up work done by the Hethel boys.  The engineering, styling and sculpting of the prototype was first rate but the factory dropped the ball repeatedly during the production run.

I struggle with whether to live with the original sloppy work or rework things to make them stronger and aesthetically cleaner.  I don't want to be accused of "over restoring".  A real frustration.

Hi My S1,

it's been interesting to read of your progress with your Europa and the issues concerning the joints between the bodyshell and the chassis.
I believe that some of the early cars may have been assembled, to some extent, by enthusiastic, younger members of staff at Hethel.

As flabbergasting as it may be, these cars were crude, simple, early examples of the (then) 'new' Europa.
It's doubtful that any two examples shared any recognised, repeatable build process / plan once the body shells were removed from the moulds!
I guess most areas of the original 'sloppy' work will end up reworked as you repair the various areas, although I don't believe that you'll be accused of 'over restoring' it.


 

[Fotog]

A lot of the mat stuff isn't meant for epoxy, as only polyesther can dissolve the weak binder, but apparently it's still mostly okay? Nice article here: https://www.epoxyworks.com/index.php/chopped-strand-mat-and-epoxy/

You can trust what the West System people tell you.  Always good information from them.  Their epoxy costs maybe 5% more than others, but their support is superior.  They're very good on the phone too.

If you don't have one, get a ribbed roller to help in wetting it out.

Epoxy with mat is only a problem if you're trying to do curved surfaces that are more than gentle curves.  Sometimes I've had success with covering the wetted surface with polyethylene sheet to help keep it in place while it gets to initial cure.  Often on overhead surfaces it will stay in place with the PE sheet, but not without. 

[My S1]

Lotusfanatic,

thank you for the somewhat positive comment.  Please don't get me wrong,  I am overjoyed to own this S1 Europa and I feel very lucky and proud to do so.  The "shoddy" assembly work is wholly  acceptable to me and it reinforces my joy of finally owning a very rare and limited production car.  It is allot like owning a prototype vehicle.  I worked for GM for twenty seven years as an automotive sculptor and I can tell you that the way we do things at GM is very much overkill.  I spent my career struggling to meet tolerances of a fraction of a mm so this Europa is a whole new world for me.

[314159td]

A lot of the mat stuff isn't meant for epoxy, as only polyesther can dissolve the weak binder, but apparently it's still mostly okay? Nice article here: https://www.epoxyworks.com/index.php/chopped-strand-mat-and-epoxy/

You can trust what the West System people tell you.  Always good information from them.  Their epoxy costs maybe 5% more than others, but their support is superior.  They're very good on the phone too.

It actually ends up being about 10% cheaper (compared to my usual "cheap" epoxy)...I paid $150 for a gallon of resin, quart of hardener, and a bunch of filler at WestMarine. Exact same items without the work pro account would have been $250, which means they're probably running about a 100% markup from the mfg pricing. West Systems is apparently unrelated to WestMarine, which was news to me. 

Fumings of the "boat tax" aside, I highly recommend the WestSystems epoxy manual, even if you aren't using their product. Lots of relevant info, especially to S1 owners: https://www.westsystem.com/instruction/user-manual-product-guide/

[lotusfanatic]

Lotusfanatic,

thank you for the somewhat positive comment.  Please don't get me wrong,  I am overjoyed to own this S1 Europa and I feel very lucky and proud to do so.  The "shoddy" assembly work is wholly  acceptable to me and it reinforces my joy of finally owning a very rare and limited production car.  It is allot like owning a prototype vehicle.  I worked for GM for twenty seven years as an automotive sculptor and I can tell you that the way we do things at GM is very much overkill.  I spent my career struggling to meet tolerances of a fraction of a mm so this Europa is a whole new world for me.

I totally agree with you that S1 Europas are similar to prototypes!
I have an S1A that requires a total rebuild (it's very rough!) and I have no idea if/when I will start to restore it....
Good luck with your car!
Mark   

[Nockenwelle]

During production the chassis has been dropped between prefabricated body sections. The floor pan is largely riveted to the underside of the chassis and not laminated there. The picture shows the floor pan/chassis area as seen from the hollow section under the seats. Lamination has mainly be used to close the gaps between chassis body where necessary. That lamination may add some stiffness to the car but I don't think that this was the primary goal.

After fully restoring my first S1A (including chassis removal) and seeing some other S1s I can say that they all look similar in the way they are built. The build quality is low, cheap and sloppy. The same is true for many engineering details. That's the way how Lotus built its cars. Chapman first goal might have been lightness but a very close second was cheap for sure.

As an example for the build quality: the other picture shows the paint job in the engine bay of my S1 (LH tank area in front of wheel arch). The paint has been carelessly applied with a paint roller and then suddenly stops where it is most probably out of sight.

@314159td I think you are doing it the right way.

Klaus