[Healeys] Seam Sealant

[Bob Spidell]

Like I said, I'll defer to Rich's experience, with two caveats: 

1) now you know what happens when you don't seal, but it probably took a couple years or more for the rust to form (how long since you restored your car?). You'll have to wait the same time to see if the sealant works (Rich probably has experience with long-term results); i.e. you need to make a fair comparison, a 'controlled experiment' (maybe you need a placebo car). 
2) I think a lot would depend on preparation and application of the sealant. To me, sealant is equivalent to body putty: works great, most of the time, but if it's not applied correctly under proper conditions you'll have problems eventually (anyone seen 'bondo bubble?'). In particular, the surface has to be properly cleaned, abraded and, most importantly, dried completely for the filler to adhere and endure. Slathering sealant over existing rust and moisture is a recipe for bigger problems than just leaving rust exposed (at least it can possibly dry eventually). I've had good results controlling rust with a treatment like LPS-3, which not only protects bare metal and inhibits rust but it's a lot easier to fog into tight crevices. So, sealant might be a great idea on a freshly dipped or blasted chassis, but not so good an idea on one that's been on the road for awhile. 

Gary, I assume your body man can guarantee he's removed all existing rust and moisture before he applies the sealant (and seals any moisture in)? 

BTW, how many concours points are deducted for non-original sealing on the underbody? 


bs 

-------------------------------- 
Bob Spidell - San Jose, CA 



> 
> I respectfully disagree with this thought Bob. The seam sealers we have 
> available today aren't the same ones that cracked and fell out of our cars 
> the first time around, some 45 years ago. A good smooth fillet of sealer 
> between under floor and chassis that takes paint is going to keep that 
> moisture out. 
> 
> Rich Chrysler 
> 

i agree with Rich. I've just removed my rear fender to repair a dent, and 
have found that rust has begun to take root between the fender lip and the 
inner lip, and on the face of the diagonal brace up to the shut face, and also 
on the corresponding surface of the inner surface of the outer fender. My 
body may (at Canepa Design, one of the best in the country) recommends 
putting a tube-applied sealant an the edges between fender and the diagonal brace 
to prevent any dirt and moisture from getting in between those two surfaces, 
since they're almost impossible to clean without loosening the fender 
fasteners, something I doubt many people (with the exception of Roger Moment) are 
going to do every year in order to keep those surfaces clean and dry. 
Without the sealant, they're particularly vulnerable to dirt and moisture thrown 
off the rear wheel, and that is the absolute top-of-the-list of the "Usual 
Places" to find rust. 
Gary