How much "play" should there be around a bulkhead

[swffan]

How much play should there be around a bulkhead? Once the bulkhead is put through the hole should there be any room at all to move it side to side or should it be a snug fit? Seems like there is a little too much "play" in the ones I'm working with.

[treesprite]

It's ok if there is a slight bit of extra room before the bulkhead is tightened, like a couple centimeters. I wouldn't want a hole with such a tight fit that I have to scrape the edges of it to fit the bulkhead in.

[zygote2k]

sounds like you are using schedule 40 bulkheads in a hole made for sched 80 bulkheads or you are using the wrong bulkhead.

[hypertech]

I want them as tight as possible because this increases the sealing area of the gasket. If your bulkhead is too small, the gasket may not be contacting glass as much as it should be.

 

There should be some room to be able to install it but if there is a lot of extra space it is probably the wrong size or type. As noted above sched 80 bulkheads use a different size hole than 40. BRS website has all the hole sizes to figure out what bulkhead the hole is for.

[dbartco]

You minght want a bulkhead tightening tool. They work great for tight spaces. If you are dealing with the bulkheads that came with the tank, they may be a little beat. I didn't give them a real careful look.

 

[Integral9]

I wouldn't want it so tight that you have a to screw the bulk head into the tank. But in reality, I think you are fine so long as it fits through the tank wall.

 

I personally like about 1/8" around the part that goes through the glass. I then tape the bulkheads in place and fill in the area between them and the glass with silicone before attaching the back (external) parts. I then tighten it down and let the silicon cure.

 

If you over tighten the gasket, you risk deforming it which could cause it to fail. Also, by overtightening you put excess pressure on the glass, which could cause any micro cracks from the cutting process to enlarge and become problems. So my advise is to make it tight, but don't crank on it like a lug nut.