Decent seam sealer

[Kayos]

It's been a while since I've worked on cars, back in the day 3M was the best around, is this still the case?

I'm looking for quality, not cheapness but I'm not doing an open cheque book build

 

[anjum]

3m, tigerseal or sikaflex. All polyurethane sealants and far better than the mastics of old. Remember to prime first, worst thing you can do is to apply it to bare metal.

 

[bump]

2nd vote for Tigerseal. Use to use it on the slotted fence post moulds when adjusting them to different lengths.

 

[lshigham]

3m, tigerseal or sikaflex. All polyurethane sealants and far better than the mastics of old. Remember to prime first, worst thing you can do is to apply it to bare metal.

I etch prime, seam seal then normal primer over the top

 

[anjum]

Epoxy prime, IMO, would be better as it's waterproof. If and when the sealant gives up the water/ damp gets trapped underneath and rusts the metal away un-noticed till it's too late.
Having said that, modern pu sealants are much better now, you are best painting over them as their UV resistance is not as good.

 

[Kayos]

It will all be painted, it's under the bonnet.

Only thing to note is the van that has the rust on an 03 plate seems to have PU factory sealant but the donor car on a T plate (with no rust) had the older softer yellow stuff

 

[langy]

Epoxy prime, then PU is my choice, I wouldn't read too much into reg plate differences.