Crack in Shower Pan

ScottG

I hesitate to bring this up on the heels of my now repaired plumbing leak, lest people start to think I'm breaking a stuff just to get attention...

As I was spending so much time crouched down on the bath floor, I noticed this crack in the shower pan:

Like most cracks that appear over winter, it starts at a screw hole or other stress point and radiates out. You can't see it well in the photo, but the crack extends down into the corner of the shower pan as well.

I've shmooied it up with some silicone sealant and it should be fine provided the lower end of the crack doesn't continue to spread. Owners might want to inspect (and repair, if necessary) inspect their own pans as a leak in this area would likely leave a puddle under the shower and potentially into the area under the driver's side bench.

Cold seems to be hard on these plastics. In addition to the much discussed cracks in the exterior trim and this crack in the shower pan, I've also experienced (and repaired) cracks in the trim around the Fantastic Fan and in one of the rear speaker covers.

jkjenn

I need to give me T@b plumbing and shower the once over, today.

ScottG

TabulaRasa said:

Drilling a small hole at the leading edge of a crack in plastic can relieve the stress and potentially keep it from propagating further.

Good point. I have some tiny drill bits so I might just give this a try.

BrianZ

I wonder if JB Weld Plastic Bond would work for those cracks?  It did a great job on our AC roof vent cap.  Comes in black or white.

4ncar

TabulaRasa said:

Drilling a small hole at the leading edge of a crack in plastic can relieve the stress and potentially keep it from propagating further.

I was going to suggest the same. It WILL arrest the crack. JB weld, or fiber glass cloth/epoxy resin...

db_cooper

https://www.walmart.com/ip/Marine-Tex-RM305K-Marine-Tex-White-2-oz/43285017?wmlspartner=wlpa&selectedSellerId=0&adid=22222222228031443416&wl0=&wl1=g&wl2=m&wl3=56384991536&wl4=pla-100828130696&wl5=1014485&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=online&wl12=43285017&wl13=&veh=sem&gclid=CjwKCAjw_YPnBRBREiwAIP6TJ__ernYiDJpc4V0RfmYhxIR1daAzfkVn668KtdlVjehkG-rQrKyBnxoCAr4QAvD_BwE

I don't have that problem (Yet!), but I would probably would try this.  I had it on hand for repairing kayaks, but one day we found our 20 y.o. hot tubs acrylic shell bubbled in a couple spots.  I removed the bubbles and put this stuff on there, and the repair is now 7 years old.  Always underwater, and 104 degrees!

GibW

Agree with the Marine-Tex recommendation 

ScottG

Good suggestions all--thanks!. I tend not to think much beyond a dab of silicone, but this could call for a bit more intervention to ensure the crack doesn't expand further into the pan.

Now that I think about it, when I was de-winterizing, I did notice a bit of water splattered on the tubing and wires in the zone just below that spot. I suspect it may have come from that crack. I might even be able to access it and patch it from the underside as well.

WilliamA

One of the best glues for plastic is also the cheapest/easiest to use. Good old model glue (remember plastic car models?) works well and applies easily.  Just make sure it's clean and dry. You can also dab a bit of paint over the glue if you're "one of those types". 
Fiberglass resin doesn't bond well to plastic and has no structural strength of its own.  Plus, it's a mess to work with. Epoxy doesn't bond well either but plastic model cement fills the crack, is strong and actually joins the pieces by melting them.  An easy, strong joint.
WilliamA 

Marceline

I'm going to preface this by saying that I helped out in a friend's boatbuilding & repair business for a few years.

I would take the time to properly repair that.  I would use an epoxy filler (like the Marinetex that someone suggested). If you hunt around, you might be able to find an epoxy filler for bathtub repair that's approximately the right color (almond, I think). The pan is almost certainly made with a polyester resin, but polyester resin is a PITA to work with. Either way, you'll only get a mechanical (not chemical) bond, and epoxy is much easier to work with (more info here: https://www.boatus.com/boattech/casey/polyster-epoxy.asp).

I would start by using a Dremel to sand a very shallow slope down towards each side of the crack. Something like 1/4" wide on each side. Sand off the gelcoat along this strip. This will give the filler something to adhere to on each side of the crack. The Dremel flexshaft attachment (https://amzn.to/2Qfb8c7) makes this job easier in tight quarters. Make sure you get the filler all the way down into the crack and across the span that you sanded. The filler should be slightly convex (definitely not concave) over the repair area when you leave it to cure. After it cures, you'll sand off that slight mound to get a nice flat finish.  For a small fix like this I've made a tiny sanding block out of a small piece of scrap wood (1x1 or 1x2) or even a piece of a yardstick. Mask off the area around the repair area so you don't scratch it up with the coarse grit sandpaper. Otherwise just follow the instructions provided with the filler.

If you want to save this for a winter project, I'd drill the end of the hole (as someone suggested) and then cover the crack with clear Gorilla tape. That would probably get you through to October.

My two cents.

BrianZ

@ScottG, I may have been mistaken about white, but JB Weld Plastic Bonder comes in "tan".  Read about it here..

J-B Weld 50133 Plastic Bonder Structural Adhesive Syringe - Tan - 25 ml https://www.amazon.com/dp/B009EU5ZNO

ScottG

Thanks for all the suggestions. It sounds like I probably should attend to this with a little more intervention than my daub of silicone.

I'm familiar with JB Weld Plastic bonder, having used it to fix some of the other T@B cracks I mentioned. JB Weld also makes something called Water Weld that is an epoxy putty that dries extremely strong and durable. I wonder if that would work much like the products @Marceline suggested?

BrianZ

I've only used the JB Weld Plastic Bonder for repairing a broken AC vent cap on the roof.  It worked great for that & was very strong for repairing the broken base of the stem that holds the mounting screw, which had snapped off when the cap got caught under a branch of our dogwood tree hanging over our driveway. 
(Tip:  when backing up the T@B we often look to see where the wheels are going, so don't forget to look up too!)

tabiphile

A word of caution...if you plan to repair a crack with an epoxy you should not do a temporary repair using anything that with a silicon base. The silicon will prevent other products from adhering. 
If you are brave, a repair I would attempt would be to carefully weld the crack with a soldering iron. Do pre-drill a tiny hole at the end of the crack to keep it from running. Once the crack is welded trim/sand any material that is above level and then carefully fill the welded groove with West Systems G-Flex. G-Flex has a very long working time so it will give you lot's of time to trim and clean the repair. Once it is set you can carefully finish it. You can color G-Flex if you want to. 

ScottG

tabiphile said:

A word of caution...if you plan to repair a crack with an epoxy you should not do a temporary repair using anything that with a silicon base. The silicon will prevent other products from adhering. 
...

Good point. I wondered about that...now that it's too late.  :-/

That's okay, I didn't use very much and if I clean up the crack well as others have prescribed I should be able to get the silicone off.

I'm not overly worried about making it beautiful; it's a very small crack, and I don't spend much time in there admiring the floor.  :-)

NomadPilgrim

My shower pan cracked too near the fastener. Over-tightened during manufacture. There's a longer thread about the flex in the flooring contributing to these cracks as well. 

ScottG

@NomadPilgrim, I don't recall the thread to which you refer, but it makes sense. I can't imagine there is anything in a camper that doesn't flex a bit while bouncing down the road.  :-)

How large was your crack, and what (if anything) did you end up doing about it?

LynEr

I have a 2018 320 Boondock and have notice a hairline crack in my shower by the far corner.  I can see no water leaking out of the trailer but am concerned this will get larger with time.  Anyone know how I might repair without removing entire shower??

tabiphile

If the crack can be "opened" enough to allow an epoxy to fill and bond, use West System G-Flex thickened epoxy to repair the crack. As has been suggested previously, a tiny hole drilled at the end of the crack will prevent it from running. I would very carefully use a dremel to "open" the crack.
G-Flex cures very slowly so it can be trimmed and shaped as it cures. That will allow you to achieve a decent looking repair. Because it cures slowly, it hardens with more flexibility and toughness than most other epoxies.  
DO NOT use any silicon products. They will prevent adhesives from bonding and repairing the crack.