bulkhead help

Wiz · Mar 3, 2017

Okay so I drilled 2 - inch and 3/4 holes in my cube for 1 inch bulkheads. The one-inch bulkheads that I have are swimming in the holes that I made. They must be a low-profile version of the one-inch. They just barely cover the hole. maybe eighth inch around the border. With a 8th to quarter inch space in between the glass and the plastic of the bulkhead. I am not sure the regulation 1-inch bulkhead will fit without hitting the corner of the tank. Question is should I buy bigger bulkheads and try or fill the hole with silicone when I install the bulkhead so if it does shift at all it will still be sealed.

dbl · Mar 3, 2017

The 1" bulkhead should be around 1 1/2". Not sure of the size you have. I personally wouldn't trust filling the hole with silicone to "fill" the gaps. That just sounds like a fail point to me. My $.02 anyway.

Even Further · Mar 3, 2017

Buy the right size bulkhead for the hole and reduce down. Or, maybe look at sch.80 bulkheads.

Wiz · Mar 3, 2017

When I looked up the fittings. It said that a 1-inch bulkhead requires an inch and three quarter hole which is why I drilled it. And I used the same bit that I did on my 75 display which worked fine. But this bulkhead is smaller than a regular 1-inch bulkhead.

Wiz · Mar 3, 2017

So you think it would be easier to buy the larger bulkhead and shave the sides so it fits?

Even Further said:
Buy the right size bulkhead for the hole and reduce down. Or, maybe look at sch.80 bulkheads.

Even Further · Mar 3, 2017

No I wouldn't modify the bulkhead. Looking at the hole size you drilled, just get 1" Sch.80 bulkheads. The specifications I've seen call for 1-7/8" or 2" hole size, you'd be fine with either.

Always follow the exact hole size that is recommended for the bulkhead. Or buy the bulkhead first, measure it, then buy the bit and be 100% sure its correct before drilling. Different brands have slightly different recommended hole sizes, then you have Sch.40 vs Sch.80 holes sizes too.

AZDesertRat · Mar 3, 2017

Are you saying you drilled the holes close to the corners? You should always stay 2x the bulkhead
diameter away from the sides so you don't weaken the glass.
https://www.reef2reef.com/threads/installing-bulkhead-tips.34973/

Wiz · Mar 4, 2017

The bulkheads I have fit fine. But they are to small. My mistake was that I thought I had a 1 inch but it is a 1/2 inch. I measured the wet side hole which is wider for a pipe. The dry side is only 1/2. I assumed both sides were the same width. Lesson learned.