> Can you describe more what mastic is and why you are using it? I am getting
> ready to redo my floor and need advice.
>
> McMaster-Carr has a pile of good materials for insulation and soundproofing.
> http://www.mcmaster.com/
> Go to: Raw Materials and Springs>Rubber and Foam Rubber

well, the mastic is a buff/brown color that is rather pliable and conforms
to shapes well.  stretchy, if necessary.  it's about 1.5mm thick, with
adhesive on the backside.  the upside is slightly textured.  at
mcmaster-carr the part no. is 9709T18.

this stuff came for something like $1.35/sf including shipping.  other
sheets come for double that, so i figured economy was next to godliness and
went with it.  once it is done offgassing i think we'll be in good
shape...but i am already used to the smell and it's not really that bad.

make sure to do a 2-step wash, if you don't want to do the full bulley and
take *everything* out and pressurewash:  dilute simplegreen, then 409 when
you're ready to stick 'em.  have a sharp knife to cut the stuff with, and be
ready to do some shape cutting to get the bulges on the slope covered
properly.

>> recommend a sealent for the bolt-ends that stick through the floor
> Just use the Silicone goo.

gonna do.

>> VW uses some sort of white goop that is
>> flexible, nonsetting, and yet thick as hell (very glue-like).  anyone know
>> where i can get some of that?
> http://www.mcmaster.com    >>> Adhesives, Sealants, and Caulk
>
> I removed that stuff very laboriously with a razor blade and needlenose
> pliers to reuse the bolts. Thought it was latex and was not for sealing but
> to prevent the bolts from vibrating loose since that is a safety issue with
> the seats.

i am reusing the bolts as is, though i did remove quite a bit.  then i am
going to put silicone sealent in the holes from the bottom side (colored
white so i can see if it falls out or not...).

good luck!
bill
'87 syncro westfalia
http://www.scruznet.com/~kasper/pics/westy/