03-29-2019, 01:08 AM
Join Date: Nov 2009
Thanked 58 Times in 57 Posts
Re: Broken corner glass
The break is on the back, right? And up top - it isn't particularly challenged with holding in a lot of water?
If it was me I'd probably just laminate a little glass patch right over the top of it. Size the patch so it's about an inch bigger than the broken area on all sides where you've got room. I'd use black silicone to glue the patch to the old glass, taking care to use plenty of silicone and try to moosh it into any voids (honestly, you could probably get it 100% waterproof, except maybe where the old silicone is):
Gather your tank, some disposable gloves (I like the blue nitriles), the silicone cement, a roll of masking tape, some rubbing alcohol, a roll of paper towels, a coffee cup of clean water, and your glass patch. Oh, and a trash container - a paper grocery bag or whatever.
- Take all this crap out into the garage. It's gonna stink.
- Lay the tank down so the broken spot to be patched is horizontal, facing up.
- Clean the patch and the break area with alcohol. Wipe dry with a paper towel. Any dust or oils really harm the adhesion. Clean your glass!
- Keep it tidy by using masking tape on the broken tank, all around where your patch will go. Lay the inner edges maybe 1/8" beyond your patch piece on all sides. Just set the patch down right where it will go, and lay your tape accordingly. I like to "go a little long" with the tape, and fold over the ends so I've got a little pull tab.
- Squeeze out a good bit of silicone onto the broken part. I'd start with a "square line" around the inside of the tape, maybe 1/2" from the tape. Then I'd do a smaller square inside that one, and another etc until there's just a dot in the center. I'd lay down the lines about an inch apart, if I was laying down a fat bead of silicone. My goal would be to have complete coverage of the glass union, with enough excess to fill all the voids in the broken panel.
- Set the patch down gently onto the silicone and press it down steadily and firmly. Keep it inside the tape border. As soon as you've pressed the patch down all the way, use a gloved finger to wipe off the excess silicone that squeezes out around the edges. Obviously, don't cut your finger. Wipe off your finger often, onto paper towels. That silicone gets everywhere otherwise. A dry paper towel is good to wipe off almost all the crap, while a damp one is good to get the last bit off your gloved finger. I usually start a job like this with a damp paper towel and 2-3 dry ones already pulled off the roll, ready to go.
- Pull off the masking tape immediately. At the last bit of pulling, when it releases it want to spring at you in a coil, and get that damn silicone all over. Control the spring and keep things clean. Or, deal with silicone smears. PITA - prevention is better.
- When you think you're ready to walk away - wait a minute. Take a few clean paper towels, dunk them in the coffee cup, wring them out, shake them open, and lay them gently over your patch. The humidity will help achieve a strong cure and union.
- Tape a nitrile glove over the end of your silicone tube, and put away your tools and materials. Leave the trash can where it is, to keep all the stink in one area. Go away for a day and let the patch job cure.
This won't look that bad at all. If you've got the materials laying around, and you're just a tiny bit handy with a glass cutter, you can do this whole job (minus the cure-wait) in a half hour. That includes sanding the fresh-cut patch edges.
Alternatively, you can remove and replace the panel. That would require demolishing your background. It also takes longer, is harder, and it's riskier in terms of cuts and more broken glass. OTOH it would also look a bit better - if you do a good job. So not worth it IMO - just do the patch.