Front chassis uprights

[richard sprint]

I have not had a good look at this yet but it would appear that the front chassis upright box section is open at the top and closed at the bottom i.e. no drain holes?

The chassis is an old but unused Lotus type and therefore would it not be sensible to provide a drain hole so that all the moisture/crud could drain away?

Any comments concerning reduced strength and or size of holes that could be drilled would be very helpful....

Richard

[type36lotus]

There should be a small approx 1/4 inch hole at the lowest point. These generally become plugged up with paint/undercoating/debris/flotsam/jetsam etc. Probe about and you should find them.

[ElliottN]

I would have a good look for the original holes before drilling. Last time I cleaned mine it took a bit of scraping and poking to locate them (amazing in such a small area). Mine are less a "hole" and more like some of the steel has been "relieved" prior to welding - on and above the seam of the weld with the horizontal frame member.
rgds,

[john.p.clegg]

Or you could do what I have done and fill the uprights with expanding foam (available from any D-I-Y store) after suitable preparation,stops them filling up with crud etc..

John

[richard sprint]

Thanks for the replies, will take a closer look...

John I used the expanding foam method for a landscape job where we used 2" dia bamboo canes used as vertical posts, we then had to fill the void back to the nearest knot to avoid them acting as water buckets.

A year later we found the foam had been acting as a sponge so removed them and replaced with a filler, I think from this experience I would be concerned they would hold moisture or have you not found this?

[trw99]

Richard

I know of two other fixes.

One is to clean out the entire upright, fill it with a primer to coat the inside (though catch it all as it comes out of the drain hole!), then fill it with something like Waxoyl to give outer protection, then seal the drain hole and fit a closing plate to the top of the turret.

Or more simply, drill out the drain hole to make it larger. Most I have seen have been in the shape of a half moon, so that those larger pieces of crud that would otherwise tend to block the hole can be forced out.

Tim

[richard sprint]

Tim

I think I'm moving toward extending the size of the hole, then at least it is a maintenance job one has some control over - i'm imagining it is similar to the drain hole of the rear spring housing which from experience only needs a flint to block the hole before the dirt and crud start to block the hole.

Probably a well directed blast from an air gun will then do the job....

[john.p.clegg]

I'd better go and check my Bamboo uprights....

John

[neilsjuke]

Do check and note that you must not drill right through as the inside has an angle to the drain hole just clean it out and then rust treatment
Neil

[gerrym]

A competent welder should be able to plate across the top openings.

This feature (ie poor design) has probably been responsible for more Lotus chassis failures than any other single feature.

Regards

Gerry

[tdafforn]

I cleaned mine out using a hoover (90% of the crud seemed to be sand so I am guessing that the previous owner live either near the sea or has sandy loam as a top soil and lives down a dirt track!)
then plastered the inside with waxoil underseal. best done using you hand (in a rubber glove).
This "should" protect it for a fair while!!
Tim

[frearther]

Regarding expanding foam, I'm pretty sure that I heard that it comes in closed cell and open cell varieties. If this is the case, a closed call type would be the only one to use. Otherwise, it's the sponge event.

[andyelan]

Hi Everyone

I'd be really reluctant to do anything like welding to the top of the upright or using expanding foam.

The key to preventing rust is ventilation. Enclosed box sections are bad news as they encourage condensation, that's why modern cars avoid them and even go to the trouble of ducting air into doors and other cavities. It's the same reason you shouldn't use car covers in damp environments or put a wet car in a garage, it just traps moisture. Of course, the inside of the uprights need to be kept scrupulously clean and the drain holes must be clear, so hoovers are a good idea and I even ues a hose pipe to flush them out if it's a nice day. As regards waxoil, only use it sparingly and allow any excess to drain. If it gets too thick, it will set and then trap moisture behind it (no matter what it says on the tin).

Andy

[bcmc33]

The Spyder stressed-skin chassis in my car has the uprights welded as a closed box structure. I've always understood that this and a few other strengthening changes from the original Lotus design is what made the Spyder chassis so much better.
And, of course, forced Lotus to stop Spyder making that chassis.

[freddy22112211]

I enlarged the holes, and cleaned and painted the insides many years ago. No trouble at all since.
Gordon