I've got an 11 yr old non-porcelain tub that has had a couple hairline
cracks in the base of it. These don't leak but I think I should do
something to get rid of the structural weakness that this sets up,
before the cracks widen.

I've got some white Bondo that I recently used for an exterior wood
repair job. All the repair info I've seen on this stuff has putting in
some fiberglass "netting", and then applying the epoxy stuff. I doubt
that's necessary for dealing with a hairline crack.

Any suggestions?

Thanks

"DaveT" wrote in message
I've got an 11 yr old non-porcelain tub that has had a couple hairline
cracks in the base of it. These don't leak but I think I should do
something to get rid of the structural weakness that this sets up,
before the cracks widen.

I've got some white Bondo that I recently used for an exterior wood
repair job. All the repair info I've seen on this stuff has putting in
some fiberglass "netting", and then applying the epoxy stuff. I doubt
that's necessary for dealing with a hairline crack.

Any suggestions?

Maybe...what IS the tub?

BTW, Bondo isn't epoxy, it is polyester resin + talc. I wouldn't suggest
it for your tub. Epoxy, maybe, but not Bondo.



--

dadiOH
____________________________

Winters getting colder? Tired of the rat race?
Taxes out of hand? Maybe just ready for a change?
Check it out... http://www.floridaloghouse.net

Dave:

Do you know the manufacturer of the tub, or even what material it's made of?

I'd phone the 1-800 Customer Service phone number of any company that makes the same kind of tub to see what they recommend. It's going to be difficult to find a material that will stand up to being submerged in water much of the time, and still make the repair smooth enough to be acceptable in a bathtub.

Also, those hairline cracks might not be deep enough to pose any real danger of the tub leaking. You might be able to eliminate the appearance of those cracks simply by cleaning the tub with oven cleaner, which I don't believe will harm anything except aluminum, so if you have aluminum shower door frames, keep the oven cleaner off of them.

What I'm thinking is that the cracks may look much worse than they are simply because they're dark and stand out against the light coloured plastic of the tub.

Soap becomes soap scum because, unlike the single valent sodium Na+ ion at the end of a soap molecule, hardness ions in your water are multivalent, like Ca++ and Fe+++, and these multivalent ions cause multiple soap molecules to coalesce around a single hardness ion. Since it's that ionic end of the soap molecule that is attracted to polar water molecules, and the rest of the soap molecule is not attracted to water at all, having multiple soap molecules surrounding a single multivalent ion causes that assembly to have very low attraction to water molecules, and that effectively causes the soap scum to lose it's solubility in water. That is, soap scum is simply a collection of soap molecules that are assembled around a multivalent ion, and that one ion isn't attracted to water enough for the whole assembly to be soluble in water.

By introducing oven cleaner, (NaOH), you effectively flood the system with Na+ ions, which drives the chemical reaction in the opposite direction. That is, in the presence of lots of Na+ ions, soap scum molecules break down to form soap molecules and hardness ions again, and those soap molecules clean up easily because they're soluble in water. Since the cracks in your tub are dark because they're filled with dirty soap, dissolving that soap in water also releases the encapsulated dirt in it, so that the dark discolouration of the cracks should disappear.

I'd put a bit of oven cleaner on your worst affected area and brush it with a nylon bristle brush (like an old tooth brush) periodically and see if it at least improves the aesthetics of your tub. You may find that having done that, your tub isn't really in any worse condition than anyone else's tub of the same vintage.

Wear rubber or latex gloves to protect your skin from the oven cleaner and maybe eye protection too. Even prescription glasses would be a good idea if you don't have any other form of eye protection. Oven cleaner is nasty stuff if you get it in your eyes.

On 9/11/2014 3:34 PM, dadiOH wrote:
"DaveT" wrote in message
I've got an 11 yr old non-porcelain tub that has had a couple hairline
cracks in the base of it. These don't leak but I think I should do
something to get rid of the structural weakness that this sets up,
before the cracks widen.

I've got some white Bondo that I recently used for an exterior wood
repair job. All the repair info I've seen on this stuff has putting in
some fiberglass "netting", and then applying the epoxy stuff. I doubt
that's necessary for dealing with a hairline crack.

Any suggestions?


Maybe...what IS the tub?

Fiberglass? Some sort of plastic? It came new w/ a new house - all I
know is that it isn't metal/porcelain.



BTW, Bondo isn't epoxy, it is polyester resin + talc. I wouldn't
suggest it for your tub. Epoxy, maybe, but not Bondo.

OK, that probably solves it - I'll have lay out a few bucks for a kit.
(To me, if you have to mix in a hardner, it's "epoxy".)

On Fri, 12 Sep 2014 03:15:43 +0200, nestork
wrote:


'DaveT[_2_ Wrote:
;3282622']I've got an 11 yr old non-porcelain tub that has had a couple
hairline
cracks in the base of it. These don't leak but I think I should do
something to get rid of the structural weakness that this sets up,
before the cracks widen.

I've got some white Bondo that I recently used for an exterior wood
repair job. All the repair info I've seen on this stuff has putting in
some fiberglass "netting", and then applying the epoxy stuff. I doubt
that's necessary for dealing with a hairline crack.

Any suggestions?

Thanks

Dave:

Do you know the manufacturer of the tub, or even what material it's made
of?

I'd phone the 1-800 Customer Service phone number of any company that
makes the same kind of tub to see what they recommend. It's going to be
difficult to find a material that will stand up to being submerged in
water much of the time, and still make the repair smooth enough to be
acceptable in a bathtub.

Also, those hairline cracks might not be deep enough to pose any real
danger of the tub leaking. You might be able to eliminate the
appearance of those cracks simply by cleaning the tub with oven cleaner,
which I don't believe will harm anything except aluminum, so if you have
aluminum shower door frames, keep the oven cleaner off of them.

What I'm thinking is that the cracks may look much worse than they are
simply because they're black and stand out against the light coloured
plastic of the tub.

Soap becomes soap scum because hardness ions in your water cause
multiple soap molecules to coalesce around a single hardness ion. Since
it's the ionic end of the soap molecule that attracts polar water
molecules, having multiple soap molecules surrounding a single ion
causes that assembly to lose it's solubility in water. That is, soap
scum is simply soap that's lost it's solubility in water.

By introducing oven cleaner, (NaOH), you greatly increase the number of
Na+ ions, which drives the chemical reaction in the opposite direction.
That is, soap scum molecules break down to form soap molecules and
hardness ions, and the soap molecules clean up easily because they're
soluble in water.

I'd put a bit of oven cleaner on your worst affected area and see if it
at least improves the aesthetics of your tub. You may find that having
done that, your tub isn't really any worse than anyone else's tub of the
same vintage.
I suspect you have an acrylic tub.

If it ain't broke, don't try to fix it. You may cause a much worse looking tub. I would try to rub some white paint into the cracks to minimize their appearance, but not try to patch it.

On 9/11/14, 4:45 PM, DaveT wrote:
I've got an 11 yr old non-porcelain tub that has had a couple hairline
cracks in the base of it. These don't leak but I think I should do
something to get rid of the structural weakness that this sets up,
before the cracks widen.

I've got some white Bondo that I recently used for an exterior wood
repair job. All the repair info I've seen on this stuff has putting in
some fiberglass "netting", and then applying the epoxy stuff. I doubt
that's necessary for dealing with a hairline crack.

Any suggestions?

Thanks

Acrylic tubs aren't strong. A good installation has a bed of plaster or
concrete under the plastic. If it isn't properly supported, it's likely
to flex and eventually crack. Sometimes you can get access to see
what's underneath.

They make special expanding foam for tubs that aren't properly
supported, if there's a floor underneath. You drill 1/4" holes in the
area around the crack and inject the foam. Then you sand it flush.

You drill a 1/4" hole at each end of the crack to stop it from
continuing. Then you fill the crack and those two holes with 2-part
polyester. You sand that nice and smooth. Then you get a spray can of
bath tub paint that's the right color. Keep applying coats until you
like it.

1. How do you fill a hairline crack with the 2-part polyester?

2. What I've read about Bathtub Refinishing Epoxy Paints, like the Klenck's product Home Depot sells, or used to sell, is that it's hard to get a smooth finish with them because the paint is thick and leaves terrible brush strokes. How do the people that do this kind of work paint the tub? With a roller, or do they spray the epoxy paint on or do they actually use a brush?

"DaveT" wrote in message
On 9/11/2014 3:34 PM, dadiOH wrote:
"DaveT" wrote in message
I've got an 11 yr old non-porcelain tub that has had a couple
hairline
cracks in the base of it. These don't leak but I think I should do
something to get rid of the structural weakness that this sets up,
before the cracks widen.

I've got some white Bondo that I recently used for an exterior wood
repair job. All the repair info I've seen on this stuff has putting
in
some fiberglass "netting", and then applying the epoxy stuff. I
doubt
that's necessary for dealing with a hairline crack.

Any suggestions?


Maybe...what IS the tub?

Fiberglass? Some sort of plastic? It came new w/ a new house - all I
know is that it isn't metal/porcelain.



BTW, Bondo isn't epoxy, it is polyester resin + talc. I wouldn't
suggest it for your tub. Epoxy, maybe, but not Bondo.

OK, that probably solves it - I'll have lay out a few bucks for a kit.
(To me, if you have to mix in a hardner, it's "epoxy".)

Before epoxy - if it were me - I'd apply some cyanoacrylate glue (super
glue). Not much, just enough so that it would wick into the hairline
crack. CA will slightly soften some plastics but once it cures the
plastic returns to its former state.

--

dadiOH
____________________________

Winters getting colder? Tired of the rat race?
Taxes out of hand? Maybe just ready for a change?
Check it out... http://www.floridaloghouse.net

On 9/12/14, 12:18 AM, nestork wrote:

J Burns;3282709 Wrote:

You drill a 1/4" hole at each end of the crack to stop it from
continuing. Then you fill the crack and those two holes with 2-part
polyester. You sand that nice and smooth. Then you get a spray can of

bath tub paint that's the right color. Keep applying coats until you
like it.

1. How do you fill a hairline crack with the 2-part polyester?

2. What I've read about Bathtub Refinishing Epoxy Paints, like the
Klenck's product Home Depot sells, or used to sell, is that it's hard to
get a smooth finish with them because the paint is thick and leaves
terrible brush strokes. How do the people that do this kind of work
paint the tub? With a roller, or do they spray the epoxy paint on or do
they actually use a brush?




This page has a PDF for professionals.

http://multitechproducts.wordpress.com/

I'm wondering how you have hairline cracks that
don't leak. Is it possible that they're just deep
scratches? If they're really cracks then it's time
to remodel the bathroom. One doesn't just glue
bathtubs together. If water gets through that you
don't know about you could eventually be faced
with a bigger job than the tub: Replacing the floor
joists and the ceiling below.


"DaveT" wrote in message ...
| I've got an 11 yr old non-porcelain tub that has had a couple hairline
| cracks in the base of it. These don't leak but I think I should do
| something to get rid of the structural weakness that this sets up,
| before the cracks widen.
|
| I've got some white Bondo that I recently used for an exterior wood
| repair job. All the repair info I've seen on this stuff has putting in
| some fiberglass "netting", and then applying the epoxy stuff. I doubt
| that's necessary for dealing with a hairline crack.
|
| Any suggestions?
|
| Thanks
|

call and get a estimate from a bathtub renisher. they should know a lot about tubs cracking.

| 2. What I've read about Bathtub Refinishing Epoxy Paints, like the
| Klenck's product Home Depot sells, or used to sell, is that it's hard to
| get a smooth finish with them because the paint is thick and leaves
| terrible brush strokes. How do the people that do this kind of work
| paint the tub? With a roller, or do they spray the epoxy paint on or do
| they actually use a brush?
|

They spray it. I've seen it done many times and it
usually looks pretty good, but it won't cover scratches
and dings in the old finish. It settles down so well that
even tiny scratches will often show through. So the
final look depends a lot on the smoothness of the
underlying porcelain. (Tiny grit scratches in the bed of
a tub aren't noticeable when it's dull, but they stand out
when a new, glossy finish is put on.)

Painting acrylic, though, doesn't
seem like a solution to me. When they spray porcelain
they first etch it with acid. Also, plastic probably flexes
quite a bit more than a steel/cast iron tub, making it
difficult for a top coat to stay stuck. I wouldn't try
anything like that on plastic unless it's especially designed
for plastic.

| 2. What I've read about Bathtub Refinishing Epoxy Paints, like the
| Klenck's product Home Depot sells, or used to sell, is that it's hard to
| get a smooth finish with them because the paint is thick and leaves
| terrible brush strokes. How do the people that do this kind of work
| paint the tub? With a roller, or do they spray the epoxy paint on or do
| they actually use a brush?
|
They spray it. I've seen it done many times and it
usually looks pretty good, but it won't cover scratches
and dings in the old finish. It settles down so well that
even tiny scratches will often show through. So the
final look depends a lot on the smoothness of the
underlying porcelain. (Tiny grit scratches in the bed of
a tub aren't noticeable when it's dull, but they stand out
when a new, glossy finish is put on.)

Painting acrylic, though, doesn't
seem like a solution to me. When they spray porcelain
they first etch it with acid. Also, plastic probably flexes
quite a bit more than a steel/cast iron tub, making it
difficult for a top coat to stay stuck. I wouldn't try
anything like that on plastic unless it's especially designed
for plastic.

On 9/12/2014 8:53 AM, Mayayana wrote:
I'm wondering how you have hairline cracks that
don't leak. Is it possible that they're just deep
scratches? If they're really cracks then it's time
to remodel the bathroom. One doesn't just glue
bathtubs together. If water gets through that you
don't know about you could eventually be faced
with a bigger job than the tub: Replacing the floor
joists and the ceiling below.

That was my thought also. Cracks never seem to stop unless drilled so
it will only get worse.

Do you use the tub for baths? If so, replace it, but if not, you can
buy a shower pan the same size and have a really nice walk in shower. I
did one bathroom last year and the second is being tiled as I write this.
This is what I used
http://www.swanstone.com/index.php?prod=383

On Fri, 12 Sep 2014 12:01:39 -0400, Ed Pawlowski wrote:

On 9/12/2014 8:53 AM, Mayayana wrote:
I'm wondering how you have hairline cracks that
don't leak. Is it possible that they're just deep
scratches? If they're really cracks then it's time
to remodel the bathroom. One doesn't just glue
bathtubs together. If water gets through that you
don't know about you could eventually be faced
with a bigger job than the tub: Replacing the floor
joists and the ceiling below.

That was my thought also. Cracks never seem to stop unless drilled so
it will only get worse.

Do you use the tub for baths? If so, replace it, but if not, you can
buy a shower pan the same size and have a really nice walk in shower. I
did one bathroom last year and the second is being tiled as I write this.
This is what I used
http://www.swanstone.com/index.php?prod=383
I suspect it is crazing feom flexing. Usually has to get pretty bad
before it leaks, but don't leave water standing in the tub for days!!!

When I install a "plastic" tub I make sure it is well supported. Last
one I did I put high density foam board under the tub then sprayed
itin with high density urethane foam. Salid as a cast iron tub. No
flex at all.

On Fri, 12 Sep 2014 05:54:15 -0700 (PDT), bob haller
wrote:

call and get a estimate from a bathtub renisher. they should know a lot about tubs cracking.
Or one of those "new bathroom in a day" companies like tubfitters.
They install a full liner in the tub and surround.

On 9/12/2014 3:51 AM, dadiOH wrote:
"DaveT" wrote in message
On 9/11/2014 3:34 PM, dadiOH wrote:
"DaveT" wrote in message
I've got an 11 yr old non-porcelain tub that has had a couple
hairline
cracks in the base of it. These don't leak but I think I should do
something to get rid of the structural weakness that this sets up,
before the cracks widen.

I've got some white Bondo that I recently used for an exterior wood
repair job. All the repair info I've seen on this stuff has
putting in
some fiberglass "netting", and then applying the epoxy stuff. I
doubt
that's necessary for dealing with a hairline crack.

Any suggestions?


Maybe...what IS the tub?

Fiberglass? Some sort of plastic? It came new w/ a new house - all I
know is that it isn't metal/porcelain.



BTW, Bondo isn't epoxy, it is polyester resin + talc. I wouldn't
suggest it for your tub. Epoxy, maybe, but not Bondo.

OK, that probably solves it - I'll have lay out a few bucks for a kit.
(To me, if you have to mix in a hardner, it's "epoxy".)

Before epoxy - if it were me - I'd apply some cyanoacrylate glue (super
glue). Not much, just enough so that it would wick into the hairline
crack. CA will slightly soften some plastics but once it cures the
plastic returns to its former state.

That's an interesting idea. That may well be the smartest first step.

Before you apply the Crazy Glue, I'd try to determine what kinda plastic the tub is made of.

Nail polish remover typically contains acetone, and acetone will dissolve "acrylic" plastic. Maybe use a Q-tip to paint some nail polish remover onto an inconspicuous area of the tub and use a flashlight to see if it dulls the gloss of the plastic there. If so, it's probably an acrylic tub.

An "acrylic" anything is an anything that's made out of a plastic called polymethyl methacrylate, or "Plexiglas". It can also be called Lucite or Perspex depending on who made it if they made it into a sheet. If it was made from other forms of that plastic, including granules, it might be called something else, including "Corian" or artificial marble. It's all the same plastic using different aliases.

I'd go to any shop that makes signs or other products out of Plexiglas and get some scrap pieces of Plexiglas out of their garbage bin. Break one of those pieces, and then try to glue it back together again with Crazy Glue. If the glue doesn't work on the Plexiglas, then I'd presume it wouldn't work on an acrylic tub either.

But, if it does work, then it should also work on your tub. Clean up those hairline cracks with oven cleaner before you start trying to fix them. Otherwise you might end up with dirt encapsulated in the Plexiglas, and hence permanent hair lines in your repaired tub.

I don't recall ever using oven cleaner on Plexiglas, but I'm quite sure it doesn't harm latex paint, which is also made of Plexiglas, but maybe check an inconspicuous spot on your tub with oven cleaner just to be sure it doesn't harm your tub.