Need help with GFPP bulkhead question:

[WhatCouldGoWrong71]

I researched that pretty heavily. There were several reasons why I wouldn’t go that route, cost is one for sure. But, it led me to www.firgelliauto.com . I’m not comfortable having my lighting rack on actuators. There is a series of “checks” to make so that I can pull it back. If it were to ever just “open” it could cause some meaningful damage. But, if you look at my cabinetry the lighting door that opens up, is going to be rebuilt and that will auto open nearly 4 feet, and will also be temp controlled. But I am going to use these controllers to lift the lighting. On the new tank.

 

[UncommonSense]

One more, would you use the bulkhead to squeeze the silcon? Or use something heavy, let it cure, then apply bulkhead?

I’ve slept on this question and given it more thought…

— my initial recommendation to press the glass plate into place to push out all bubbles still ring true, at least partially…

— My initial concern with using the bulkhead to clamp the new glass plate down was that the excessive silicone will squeeze out into the bulkhead hole; effectively gluing the bulkhead in place!


However, now I propose a hybrid solution of manually pressing the glass plate down to start, and finishing by clamping with the bulkhead fitting!

Here’s how/why:

If you press the new glass plate down onto the bottom of the tank only by hand, then let it sit and cure; the silicone is so viscous that the new glass plate isn’t guaranteed to be sitting perfectly parallel with the bottom pane of the tank itself! — this could cause bulkhead gasket issues, and glass stress issues (clamping a flat bulkhead seal on a slightly slanted surface)…

— so, why not remove the rubber gasket from the bulkhead fitting, then either masking tape the bottom of the bulkhead flange and threads, or use petroleum jelly on them as a “mold release”?

— this allows you to press the bubbles out of the new glass plate’s silicone bond by hand, wipe off the excess silicone that’s squished out into the bulkhead hole, then install/tighten the masked (or mold release coated) bulkhead to ensure the new glass plate is nice and parallel to the existing tank bottom before the silicone skins over!

Then, come back the next day, or next week to remove the bulkhead and proceed with plumbing!

 

[UncommonSense]

I was wondering about how to apply the silicone. I was worried about air pockets.

I just finished up a test of this process, and figured I would follow-up here!

This application is simply siliconing (ASI 502 clear) a 3” wide piece of 1/4” acrylic to the back wall of a 1/4” acrylic sump, effectively doubling the material thickness for additional strength when an ATO float hole is drilled! (For my LFS)

I applied a ~3/4” thick bead of silicone, roughly centered on the 3” wide plate….

Then pressed it into place on the sump wall; squishing out as much air as I could from the bond… (note; white marks are scratches on scrap acrylic piece being added, not air bubbles! — those are in the corners!)

The silicone seemed to effectively squish out up to 1” total per-1/4” of silicone bead thickness…. I would estimate closer to 3/4” squish per-1/4” of bead thickness in your application to not have the new glass plate pressed down tight to the tank bottom!

— I hope this helps, and I hope you’re making good progress on sourcing glass over there?

 

[WhatCouldGoWrong71]

Hey, this is great. The 1/4 to 3/4 ratio is great. Yep, I was able to ask Joe if they could cut and drill this for me, and they can. I’m thinking 1/2” for piece of mind. He asked if I can just sketch it up. I’m thinking I want 2” outside of the hole. So if the hole is 2.63” or 67mm, then the piece of glass should be 6.63”x6.63”x1/2”.

 

[UncommonSense]

Hey, this is great. The 1/4 to 3/4 ratio is great. Yep, I was able to ask Joe if they could cut and drill this for me, and they can. I’m thinking 1/2” for piece of mind. He asked if I can just sketch it up. I’m thinking I want 2” outside of the hole. So if the hole is 2.63” or 67mm, then the piece of glass should be 6.63”x6.63”x1/2”.

This should work great!! Maybe make it 6.75”X6.75” just so it’s less of an oddball measurement for them to cut?

Hopefully you can get the edges on one face of the glass plate beveled? — like the acrylic plate in my reference photos above!

Failing that, I recommend requesting that they at least smooth the sharp edges on one face of the glass plate! It’s some SHARP stuff!

Given that you’re going with 1/2” glass thickness, you will likely want to consider getting the “long” version of your Hayward bulkhead!

I’m glad you’re back on track! Keep up the good work over there!

 

[WhatCouldGoWrong71]

Thanks my friend. Yes, 6.75 makes more sense. No issues on the bevel. I’m going to have the bulkhead overnighted tomorrow. I’m going to photo document/video the fix for others that do dumb crap like me.