Sealant for wheel arch closing plates

[Bigbaldybloke]

Hi all, I've done a search and didn't find anything specific regarding the best sealant to use around the wheel arch closing plates. I've made new alloy plates as the originals were not in good shape after being removed by others to fit new stainless steel sill members. Interestingly the left and right hand sides are not exactly mirror images, but the new ones which are exact copies of the originals do seem to fit well when held in place. The question is what is the best sealant to use to seal around these plates, there has been a lot of progress on better types of sealant such as silicone since the car was first built 50 years ago so I'm interested in what people have used recently and how it has held up in service. I have bought some rubber u shaped seal that I could put over the edge of the alloy where it goes against the wing and silicone or some other sealant between the plate and the inner wing which the plates are secured to. Just a thought has anyone filled the sill members and possibly the volume behind these plates with closed cell expanding foam, would need to be careful to allow it expansion room.
Anyway advice on sealants is the main question here, what works and any tips on securing the plates, pop rivets, self tapping screws or small nuts and bolts.

Thanks
Simon

[mbell]

Hi Simon,

I made some front ones out of black ABS sheet as mine were missing. Sounds Like i did the same as you, rubber U on outer edges to wings and black silicone sealant to seal inner edges. I just used pop rivets to fix them in place, with dab of silicone. Rear ones are showing there age and at some point I'll follow the same route for them.

Also wondered about the expanding foam route but didn't do it, for concerns over it's expansion and possibility to trap moisture. I suspect some type of foam or other material would be beneficial for noise reduction.

Cheers,

Mark

[Concrete-crusher]

It's important to remember silicone is just a gap filler not an adhesive , I would suggest a PU based product like mapeflex pu45 , or Sikaflex 11fc but you could also look at the newer MS based sealants.

Personally I prefer the PU,s

Steve

[Sea Ranch]

Just about to do the job, too, having made new plates out of .040" aluminum.

I plan to use a polyurethane "body sealer", a product used in NA to seal body panels, fill gaps, etc. I've used this in various places and am happy with it's adhesive strength, cured consistency, etc.

Would like to use push-in center-pin type fasteners similar to originals but haven't chosen them yet. Planning on lots of masking tape and a big fat bead of sealant along the inside of the fiberglass "wings", as you call them, that the closing plates can then push up against and adhere to on that side. Sealant bead under the straight edge.

Not that these plates need to actually seal, as any water will seep through the lower edge of the sill. But it seems good to keep out as much dirt as possible. I have stainless sill members installed so I'm not worried about corrosion.

Show us pix when you're done

Randy

[Sea Ranch]

It's important to remember silicone is just a gap filler not an adhesive . . . Steve

Don't tell that to people who regularly glue glass panels together with silcone sealant to make fresh and salt water aquariums . . .

Randy

[NedK]

Adjacent thought...

After fitting the new S/S sill members, I plan to put a bead of Sikaflex or similar in the gap on each side of the 'blade' at the bottom, so that when the bolts are nipped up along the sill, there is some sort of seal to keep out the weather.

Hopefully this, plus the sealed end plates, plus the stainless sill... The original ones I removed from the car were largely powdered rust!

Ned

[Sea Ranch]

Just my personal opinion, Ned, but I don't believe it's possible to seal anything permanently. Which is to say, that cavity in and around the sill member will get water in it. The best way for the water to drain is through the bottom flange.

Not to mention, of course, the fact that the Plus 2 has a couple holes in the fiberglass sill, front and back (jacking point access). Or are you planning on fiberglassing those over?

Do still like the idea of making the closing plates seal as well as possible, in order to keep junk out of the cavity.

Regards,

Randy

[Bigbaldybloke]

My sill members are bonded in but I'm not worried about water collecting in there because as Randy points out, it can drain through the jacking point holes, and anyway the car is unlikely to get much use in the rain!

[NedK]

All good points!

[stugilmour]

I also used some sort of body sealer I got from the parts store around the plate edges.

Haven't seen mentioned yet, but I overcoated the plates and sealed edges with black undercoat material. Stuff I used is in a standard spray bomb. It expands slightly when sprayed, so a couple of coats seal the plate edges very well.

I think this is the stuff I used. Great stuff to black out the bottom lip where the bolts are fastened.

http://www.canadiantire.ca/en/pdp/rust- ... p.html#srp

Cheers!

Stu

[Bigbaldybloke]

Just cleaning up prior to fitting the new rear cover plates and two things struck me. One, need access behind it to fit the door pillar part of the door lock, and two, the seat belt mounting looked a bit rusty. This is the drivers side seat belt mounting plate after I removed it

[Sea Ranch]

Love it. Yup . . . a bit rusty

Randy

[Bigbaldybloke]

I went for good quality black silicone sealer in the end, didn't want to bond them in place in case I needed to remove them some time in the future. Pictures attached of one plate all sealed in place, also a before and after of the seat belt mounting, these were in a truly shocking state once you gave them a quick tap with a chipping hammer. Still haven't fitted the rear closing plates as I haven't found the door lock plates - early type.