How can I fix a small crack in a plastic bath

[CadwellParker]

Hi all,

I have a plastic (acrylic?) bath which is about 7 years old. It has been damaged by one of those cheap wire soap dishes that attach to the wall tiles using suckers falling into it. There's a chip on the inside of the bath and a small crack through to the other side, small but big enough to allow a trickle of water through. Is there any way of repairing this and avoiding the expense of buying a new bath, fitting it, re tiling etc?

Someone suggested filling the crack with super glue or silicone. Someone else suggested a fibreglass patch on the back. I thought the repeated heating and cooling would eventually cause the leak to start again, if such a repair even stopped it in the first place.
What's the best thing for me to do please?

 

[alan333]

I made quite a big hole in an old acrylic bath while removing the wall tiles above. I was fitting a new bath in the following weeks, but wanted the old one water tight in the mean time. Obviously I didn't care what it looked like, so I repaired it using fibre glass underneath (it was quite unsightly from the top, due to the size of the hole). The repair was solid and well stuck, and held water during the following few weeks. That bath always had a fair bit of movement when showering etc, which turned out to be that one of the leg supports had been cut through by the previous owner... However, even with all the extra strain and movement, the repair didn't fail.

If yours isn't as bad as mine, try fibreglass underneath to physically support the structure and for waterproofing, then if it's unsightly, whatever you can think of on top to please the eye. Silicon would probably work but you'll always see it. Araldyte 2 pack glue would also work but it's clear in colour, maybe it's also available in white?

 

[Madrab]

Depending on the size, you need to drill the hole to remove the cracks, if left they will grow. Then you simply need to get a hold of an acrylic bath repair kit. It has specific compounds that allow small damage to be repaired, you will also receive whit enamel that will allow you cover the repair.
If you have used fibreglass matting and resin before and know how to properly prep and apply on the outside, then that can be used for a permanent repair and then use acrylic filler or flexible body filler for the inside of the bath, flatten and then cover with apline white enamel.

 

[CadwellParker]

Ok thanks, that's good to know it can at least be mended. I've not used fibreglass matting before but I'm sure I can find out easily how to prepare and use it properly.

Depending on the size, you need to drill the hole to remove the cracks, if left they will grow.

So how big can the hole be before it's too big?

 

[Madrab]

If you are using fiberglass sheeting and resin then it can be pretty big. Repair kits are different as they don't use fiberglass sheet therefore there is no support for the filler.
As long as the area is well prepared, rubbed down with an 80 grit paper, then cleaned really well and the resin and hardener for the fiberglass made up correctly. If you're good with that kind of thing then it won't be a problem. Drilling out the cracks stops them from getting larger.

 

[CadwellParker]

Thanks for that. The outside surface of the bath, the that is supposed to stay dry is already quite rough. It looks like the rough side of a fibreglass boat for example. Would I need to rub that flat before applying the sheet and resin?

 

[alan333]

Take the high spots off so there's a reasonably flat area for the new fibreglass matting to bond to.

 

[CadwellParker]

Ok, thanks Alan, that's really helpful. Cheers.

 

[Jackrae]

Homebase do a 2-part resin called Atmos Paste. This designed to repair chipped porcelain sinks, baths etc. As it's white it should do a reasonable job of the inside damage to the bath. I've also used it in the past to seal defective fitting threads (acting as a filler between male and female threads) Only drawback is that the joint can never be dismantled once the paste has set.

 

[Madrab]

Yup, as Alan says, lower the high points and using some 80grit sandpaper to roughen the acrylic coating on the back to give the sheet and resin something to bite/grip to.