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Jim Yanik

(Chris Lewis) wrote in
:

According to Jim Yanik :
(Chris Lewis) wrote in
:

- Scuff sand the affected area, swab with alcohol.
- Lay down 2-3 layers of fiberglass (top layer 2oz if available)
with an inch or two overlap on the crack.

that will leave a very obvious patch visible no matter how good you
are.

With West and the aforementioned shrinkwrap, being "obvious" is
almost entirely a matter of color match. If you can get a good one,
it can be practically invisible. Far easier/better than trying to do
the entire bottom of the tub, because trying to get _that_ faired
properly, hidden edge or not, will be almost impossible.

Compared to a small patch in the middle of the tub bottom?
THAT is going to show much more than a whole tub-bottom covering,even if
you match the color and smooth it perfectly.
It WILL still be a raised patch on the flat tub bottom.
IMO,MORE obvious than a whole-bottom covering.

and fairing a whole-bottom covering is NOT "almost impossible".

[We term this "mexican prison wall finish"]

Tub should be useable in 3-4 days. If it's takes longer, you can
coax it a little faster with a hair dryer (keep the epoxy _under_
150F).

Epoxy doesn't *fully* cure in 3-4 days.

Concrete only fully cures after 30 days.

SO WHAT? we ain't talking about concrete.

You don't have to wait that
long to use it. Epoxy is going to be at 95% or better in 3-4 days.

Don't bet on it.

Especially if you tickle it along with a heat gun.

[The West Systems instruction book is quite good.]

So is System Three's Epoxy Book.

It's more important to ensure you get the proportions right. If you
don't, it never cures.
Agreed.

Your patch would not gain full strength for a couple of weeks.Putting
a person's body weight on it would likely break the bond or it would
crack at the original crack.

There's no way epoxy will break bond off a fiberglass tub prepped
as I've suggested. Yes, the original crack is a weak point. Depends
on why it cracked. And is why I suggested a thick/sloppy patch on the
backside too if you can get at it.

A backside patch is the best way,of course.

--
Jim Yanik
jyanik
at
kua.net