Hi, I'm currently in the process of changing the clutch,I've only owned the car for a few weeks. Anyway about half the bolts securing the under tray are missing and it's been held on by zip ties in various places. Anyone know where I can get some new ones ?
They are standard M6 x 1.5 thread. Most undertrays (the ones that are still on the cars that is) are held on, in good part with cable ties. You might find yourself drilling out some sheared bolts and re-tapping, hence the cable ties.
Quote from: Mr2highpeak on February 26, 2022, 16:21Hi, I'm currently in the process of changing the clutch,I've only owned the car for a few weeks. Anyway about half the bolts securing the under tray are missing and it's been held on by zip ties in various places. Anyone know where I can get some new ones ?
They're usually around £1.50 for a pack of 10 at Screwfix.
Quote from: Call the midlife! on February 26, 2022, 16:53They're usually around £1.50 for a pack of 10 at Screwfix.
the bolts ?
Quote from: Mr2highpeak on February 26, 2022, 17:01the bolts ?
Yup, I keep a selection of them on the shelf but the 16mm stainless are just right for the trims, with a washer but those are also cheap as chips from Screwfix.
Quote from: Mr2highpeak on February 26, 2022, 17:01the bolts ?
https://www.screwfix.com/p/easyfix-a2-stainless-steel-set-screws-m6-x-16mm-10-pack/9308t
Other lengths are available, you may also like to add some large diameter/ penny washers, same source.
Edit predictive text corrected!
The penny washers can be a bit too big for some of the recesses in the undertrays but good to keep on hand.👍🏻
Excellent thanks, I will pick some up along with some washers.
We are very good a saving you money on otherwise unnecessarily expensive items.
If its a serious matter. We start at the cheap end of solutions and work up.
Otherwise we are also be very useful for helping you spend your money on bling.
Quote from: Mr2highpeak on February 26, 2022, 21:08Excellent thanks, I will pick some up along with some washers.
A tap to run through the holes first is a good investment as well, assuming you don't have to drill any old, sheared screws out.
Quote from: Call the midlife! on February 26, 2022, 22:47A tap to run through the holes first is a good investment as well, assuming you don't have to drill any old, sheared screws out.
doesn't appear to be any sheared bolts that I can see.
There's a good chance of galvanic corrosion replacing the standard metal bolts for stainless steel bolts, (https://en.wikipedia.org/wiki/Galvanic_corrosion) in my opinion maybe using cable ties or nylon bolts are a better choice if you're not planing on using like for like bolts
When I replaced my dampers on my Elise (has an aluminium chassis structure), at the same time I also had new non aluminium metal brackets for the dampers and had to use Duralac Anti Corrosive Jointing Compound between the two different compound metals to prevent galvanic corrosion
https://www.mbfg.co.uk/duralac.html
Only my opinion, maybe many won't get this galvanic corrosion
Galvanic corrosion can occur when two dissimilar metallic materials are electrically connected in a corrosive environment. ... When stainless steel is joined with carbon steel, for example stainless tubes and carbon-steel tube plates in a heat exchanger, the carbon steel may suffer from galvanic corrosion attack.
https://www.materials.sandvik › galv...
In the case of your aluminium alloy Lotus and mild/ carbon steel brackets I believe there is some need for concern.
But, on our 2's we are proposing the use mild/carbon steel brackets and stainless steel fixings. They are both steel one alloyed with Carbon and one with Chromium.
For some perspective I replaced the under tray fixings , cable ties, with stainless steel machine screws as one of the first jobs when I bought the car in 2011. They are removed for service access each year. The car is garaged and SORN in winter. The fixings have not disintegrated nor has the attachment point.
For galvanic action an electrolyte is necessary. Water, particularly salted water as " available" in the winter months could act as such , but I doubt that this would be noticeable as they will be removed on an annual basis for service access and cleaned and a spot of Copaslip applied before replacement.
I didn't know it had a name but I stopped replacing bolts with "stainless" bolts because quite frankly they were doing more harm than good. They all started to corrode
Quote from: shnazzle on March 1, 2022, 10:01I didn't know it had a name but I stopped replacing bolts with "stainless" bolts because quite frankly they were doing more harm than good. They all started to corrode
As soon as you touch them with the socket and knock the surface they'll start to deteriorate, same as the threads going into the hole.
But they last plenty longer than the mild steel ones and I tend to run a tap through the holes before putting any new screws in, with a judicial amount of chosen lubricant/preventative compound.
But I generally take mine off at least once a year to do those standard maintenance jobs like taking the engine out...😂
Stainless steel isn't a catch all term. There are different grades you know:
https://u-bolts-r-us.co.uk/blog/16_grades-of-stainless-steel-a2-a4-in-relation-to-fasteners.html
Yup. The Screwfix ones used to be A10, which is plenty good enough for the task but I think they've downgraded them now.
They'll still do the job.
When I use stainless fixings or make anything out of stainless I always try to use 316 (A4) as used in a lot of dive watches.