Questions about pre-fabricated sill repair panels

Technical Area Body, Interior & Styling
2

Hi,

I’ve just joined this forum, and would appreciate some advice.

I bought a 2002 MK2 MX5 about a year ago, and it’s in generally good condition. Unfortunately however, both sills have rusted in the usual place just in front of the rear wheels. I’m therefore considering getting new panels welded on to fix the problem.

I’ve had several quotes from local garages (I live in Tunbridge Wells, Kent) and also from The MX5 Restorer. Although the quotes are the going rate for this type of work, they seem a little high in relation to what I paid for the car. I’m therefore thinking that, as I already own a welder, I might have a go at carrying out the work myself.

Although I’m willing to have a go at the welding, I’m not so keen on the idea of fabricating my own repair panels. So I’ve been looking at the various pre-fabricated panels that are available.

I’ve found some full wheel arch & sill replacement panels on Ebay (and various other places) for £149.99 a pair, including postage. These panels are designed to repair the sill and wheel arches. My wheel arches are in good condition, so I’d need to cut the panels down to size, in order to repair just the sills.

There are also some other smaller panels on Ebay that are designed just for repairing the sills. These panels cost £88.05 (including postage). On the face of it, they would seem to be a better option for me because, if I bought the full panels, I’d have to cut off the sill sections and discard the rest, which is wasteful. However, the smaller panels do have a slightly home-made look to them, and the metal they’re made of is only 1.2mm thick, which seems a little on the thin side. That wouldn’t necessarily be a problem if they were priced accordingly. But they do seem a little expensive for what they are.

Also, from the pictures, the full panels appear to be galvanised, (although I haven’t checked this with the seller yet). This seems to give them another advantage over the sill-only panels which appear to be covered with black paint.

My dilemma is whether to buy the full wheel arch & sill replacement panels, which appear to be better quality and better value for money (but end up discarding two-thirds of the metal), or just buy the cheaper sill-only panels.

So, I’m wondering whether anyone here has used either of these panel types, and if so, which would they recommend. Also, are there any other options available?

Thanks in advance for your help.

(p.s. I considered posting links to both panel types, but I wasn’t sure whether this would breach forum rules.)

3

Most repair panels fit ok 

As to having  galvanised or not make sure you clean the galvanising off a good bit from the weld as its a bugger too get a nice weld otherwise 

also burning galv isn’t that good for you 

If you get the galv panels that is .

4

https://www.doctormx5.co.uk/what-we-do/sills-and-welding/      They did my sills a few years ago and were very reasonable in price.

5

Hi

I have looked for galvanised repair panels and cannot find them. To be honest I would doubt they have a proper galvanised finish. As mentioned any coating would need to be removed near the weld area which is where rust is most likely to occur first.

I think the standard metal gauge is 20 gauge. The smaller panel is 1.2mm, 18 gauge so the seller’s claim that the panel is made from thicker steel than standard is probably fair. This seller has also been selling these panels for some time. Did you say that the larger panels are made of thicker metal? - I can’t see that mentioned but could have missed it.

Choice of panel is down to the level of corrosion. From my experience the small panel would have been too small for my repairs even though there was no rust in the arches. 

I spent hours making my own panels up - don’t even think about it! a very complicated shape, difficult to get right. It worked well in the end but was a silly challenge when perfect panels are available.    

 

6

The usual problem here of a similar amount of work to do to repair a section of an old car that cost £1,000 and a similar item on a £6,000 car. As you have found the price is the same and at first look it seems but “that is near the price of my car”.

Yes that is the cost of running an old car you either pay by buying a newer car or pay more times for repairs on an old car. You very rarely get the best of both worlds. Just tough.

As already advised any galvanised coating is burned off when welding or is dangerous to breath the fumes while the welding is done.

If the arches are looking good just wait say six months and they may well need done.

If the outer sills are rusty, the inner sills are probably rusty as well and these will need replaced or repaired so some fabrication work will need done and you need to get the internal parts primed and cavity protected with something like BiltHamber Dynax S50 or a similar product after welding.

The cost of the panels is virtually nothing to do with the steel thickness as that is inexpensive bit. The expense is the work to get the shape correct and to reduce the fitting work required. If you think they are too thin contact other vendors until you get what you want but they may all be a bit thin.

Then it needs filled, rubbed down and primed and painted.

I can weld a bit but can guarantee I would make a mess of the filling and painting, good to know your limits!!!

You may well be better at the finishing trades.

Inner sill picture just to wet your appetite.

https://www.google.co.uk/search?q=mx5+inner+sill+repairs&client=firefox-b&dcr=0&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiM8K_WwOnYAhWjOsAKHazXDQUQsAQIOg&biw=854&bih=382#imgrc=Qi7jmNOSTNw_-M:

How to get the goo behind the outer sill after welding.

http://www.mazdamenders.net/forum/viewtopic.php?f=37&t=1324

7

Is your welder a MIG or a stick welder.

8

Thanks for the replies.

As links do seem to be permissable, I’ll post some links to the panels I’ve been looking at:

https://www.ebay.co.uk/itm/NEW-PAIR-MX5-Eunos-Miata-MK2-MK2-5-Rear-Sill-Repair-Panels-Both-Sides-Schweller/232447790084?fits=Model%3AMX-5&hash=item361ef7cc04:g:0WQAAOSwTEJaHx8k

https://www.ebay.co.uk/itm/Mazda-MX5-MK2-Rear-Wheel-Arch-Sill-Replacement-Panels-Pair-New/372195572035?fits=Model%3AMX-5&hash=item56a895b943:g:qwwAAOSwYwJZ7eOP

I’ll also try to answer a few of the questions that have been asked:

Is your welder a MIG or a stick welder.

I own a MIG welder.

If the arches are looking good just wait say six months and they may well need done.

I’ve carefully inspected the arches and can’t find any evidence of rust. I wouldn’t even contemplate doing this work if there was even the slightest chance of having to fix the wheel arches as well!

I have looked for galvanised repair panels and cannot find them. To be honest I would doubt they have a proper galvanised finish.

Well, for what it’s worth, the company selling them on Ebay (MX5 Heaven) are describing them as “Supplied in a galvanised finish”. Of course that doesn’t necessarily mean they’re genuinely galvanised. That’s why I’m interested in hearing from people who have actually used them.

 

 

9

Hi yes I got the complete sill / arch panel from mx5 heaven yes it was galvanised and you do need to give it a good clean up before welding. It was a really good fit and the metal thickness seemed good. I actually cut out of it what I wanted which was the arch and sill. The cutting and welding part isn’t too bad of a job but I am going to get a professional to do the paint. Be prepared for the inner sill to require some attention mine was awful and had to fabricate a panel for that and also a panel for the inner arch. All good fun and hopefully will last for a few years! 

Just noticed yours is a mk2 sorry mines a mk1!

10

Give MX5 Heaven a ring and check with them  - please report back. I would guess that is a BZP finish and the metal is 18 gauge, 1.2mm

Very difficult to properly access the extent of the rust without an interior check which would require some invasive inspection. Hopefully the rust is limited to the lower part of the sill but exterior appearance is only a rough guide.

MIG welder is the right tool. Arch skins are spot welded and a joggler would blend the larger panel in if a more major repair required.