Cracked Bulkheads. Was it the sealant or too tight?

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Pedal Dangit

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I'm pretty sure I only tightened these by hand, but I seemed to crack two out of three. I admit I do have some heavy auto mechanic hands. Was it the sealant maybe? It is still gooey and it didn't dry hard. Also, does anyone know for sure is the sealant aquarium safe? I couldn't find anything else to use at the local hardware store.

I kept breaking it apart on purpose to show the cracks but at first I didn't even notice them until I ran with water. I thought it was the seal and took me a bit to figure out they were cracked.

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JoshH

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Did you thread them in all the way when you first installed them? And it does look like a lot of sealant but that shouldn't be a huge problem if you only snug fit them.
 
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Pedal Dangit

Pedal Dangit

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Looks like you clamped em down to hard ands they busted. Also there should be a gasket in place and as long as that gasket is there you shouldn't need any thread sealant.

Gasket? ummm, only on the wet side of the flange. I'm only talking the threaded part at the bottom where the MPT/slip adapter attaches.
 
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Pedal Dangit

Pedal Dangit

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Did you thread them in all the way when you first installed them? And it does look like a lot of sealant but that shouldn't be a huge problem if you only snug fit them.

That looks like combination of both. Tightening too much plus added stress of sealant.
Pvc threaded fittings don't need any sealant or tape. They are supposed to go on as is and tightened by hand and then by tool slightly.

I tried to assemble dry but they didn't want to go together very well (catching and grabbing / not smooth) and I read that you are supposed to use thread "lubricant" which I couldn't find. This stuff was cheap and said it doesnt dry hard so I thought I would try it since it says NSF on it. After I put a little on the first 3-4 threads of the male end they went together really easily. And I snugged them down by hand until the sealant kinda oozed out where the thread ends. Yes, I'm pretty sure they went all the way in, but again all by hand. I have to order some more fittings and I was just wondering if I should use the stuff again and go real easy tightening?
 

Sierra_Bravo

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There's nothing wrong with using Rectorseal #5 - it's a non-hardening sealant that can and really should be used for threaded connections. The sealant (not a lubricant although it can act as one) fills any leak paths there may be through the thread connections.

Yours busted because it's over tightened. PVC threads are tapered to compact them together and seal any path that may cause leaks, but they act as a wedge if you seat them all the way like that. The female end just won't withstand the force like metal fittings do. PVC threaded fittings should be hand tightened until they stop, then use a tool to tighten 1.5 more turns. That should be all you need.
 
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JoshH

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There's nothing wrong with using Rectorseal #5 - it's a non-hardening sealant that can and really should be used for threaded connections. The sealant (not a lubricant although it can act as one) fills any leak paths there may be through the thread connections.

Yours busted because it's over tightened. PVC threads are tapered to compact them together and seal any path that may cause leaks, but they act as a wedge if you seat them all the way like that. The female end just won't withstand the force like metal fittings do. PVC threaded fittings should be hand tightened until they stop, then use a tool to tighten 1.5 more turns, That should be all you need.

/\ what bravo said. If they went all the way that's too far, you used sealant correctly just a few too many turns. :) Because the sealant acts as a lubricant it will let you turn them all the way in but because the threads are tapered it will end up splitting. There should be a 1/8" to 1/4" gap between the two. Remember the sealant on the threads will do just That, seal the threads so you don't need to go all the way.
 

fermentedhiker

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That's why I only use Spears on new builds. Unfortunately they require a different hole size for a given size pipe :( They are true PVC and not ABS have larger threads and can be hand tightened with ease. Well worth the extra cost IMO
 
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Pedal Dangit

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Thanks to everyone for the quick replies / help. I will follow up when I get them installed. Will just try a delicate touch on them rather than twisting them all the way in.

That's why I only use Spears on new builds. Unfortunately they require a different hole size for a given size pipe :( They are true PVC and not ABS have larger threads and can be hand tightened with ease. Well worth the extra cost IMO
This is how I remember them going together, I believe I just used my grip strength to twist them the final turns. No tools used.
I was kinda wondering if they are just poor quality bulkheads.
 

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Here’s your problem-
424a8739c8f713478299c8ea8b9f3c7f.jpg


You need to use rectorseal T plus2 on ABS bulkheads. It’s in the white tube

You used R5. It literally ate your abs. Only takes like 6 hours to do.

I did the same on a cheap eBay pump that had an abs volute. The thread on the output snapped off after 6 hours. I rebought, used T plus 2 and it’s been inuse leak free or 6 months.

Here’s what I ended up with-
2608bc80c8bf83e0af53f710daab6e65.jpg


It now sits in my plumbing box as a reminder to read the f’ing label

3bc3778937ee7c25a13b23ca3c07f78e.jpg
 
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There's nothing wrong with using Rectorseal #5 - it's a non-hardening sealant that can and really should be used for threaded connections. The sealant (not a lubricant although it can act as one) fills any leak paths there may be through the thread connections.

Yours busted because it's over tightened. PVC threads are tapered to compact them together and seal any path that may cause leaks, but they act as a wedge if you seat them all the way like that. The female end just won't withstand the force like metal fittings do. PVC threaded fittings should be hand tightened until they stop, then use a tool to tighten 1.5 more turns. That should be all you need.

Except you can’t use R5 on ABS. Literally says that on front of the tube. It’s just for metal tube.

Abs requires rectorseal T plus 2 in the white tube.
 
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fermentedhiker

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This is how I remember them going together, I believe I just used my grip strength to twist them the final turns. No tools used.
I was kinda wondering if they are just poor quality bulkheads.[/QUOTE]

As far as I'm concerned ABS bulkheads are poor quality.....period. They are on thousands of tanks though so clearly they can work. I used Spears on a custom acrylic build and I'll never voluntarily use anything else in the future. Unfortunately they require a bigger hole in the glass(they are schedule 80 pvc after all) so you can't replace an ABS one with them without redrilling which could be tricky.
 
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Pedal Dangit

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Here’s your problem-
424a8739c8f713478299c8ea8b9f3c7f.jpg


You need to use rectorseal T plus2 on ABS bulkheads. It’s in the white tube

You used R5. It literally ate your abs. Only takes like 6 hours to do.

I did the same on a cheap eBay pump that had an abs volute. The thread on the output snapped off after 6 hours. I rebought, used T plus 2 and it’s been inuse leak free or 6 months.

Wow, thanks! I didn't even think to realize the bulkeads where made from ABS. (not that I really read that part anyhow) I just read down until I saw "use for PVC" and then my eyes were drawn to the NSF circle and the box it was in said safe for potable water. And it was cheap.

This forum is awesome. thank you all so much. I wonder how many other people have had the same thing happen.
 

77.christy

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Use Teflon tape on your threaded joints. Hand tighten and then another turn it so with channel locks or something. Not every mechanical joint is the same so there is no “set” 1/4, 1.5, etc rule for tightening. Like stated, if it bottoms out, it’s way over tightened. Another thought to consider. Out returns are open ended. Meaning they’re never fully pressurized like your water lines in your house. So, there really isn’t a need to go all hulk hogan on them. [emoji23].
 

Sierra_Bravo

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Shouldn’t this be ‘hand tightened, then 1/4 turn more with a tool’?

Not 1.5 more times.

Man, I'm getting put on defense here! :D

Straight from Lasco:

The "Do's and Don'ts" of Assembling Threaded Plastic Fittings
Today, there are millions of miles of plastic piping with threaded fittings, providing reliable, leak-free service. However, a tiny percentage of those threaded plastic fittings may leak or break. The reason for this is improper assembly of threaded joints.

Here are some of the Do's and Don'ts of PVC joint assembly:

  • Don't over-tighten joints by giving them "one more turn to be sure."Do finger tighten plus one or two turns - No More.
  • Don't wrap Teflon tape or Teflon paste or pipe dope to add bulk to or to lubricate the joint. Do use a sealant for threaded joints.
  • Don't use "stronger" Schedule 80 threaded fittings on the assumption that they may solve the problem of splitting through over-tightening.
  • Do use only Schedule 40 threaded fittings with Schedule 40 pipe and fittings.
  • Don't over-tighten.
  • Do finger tighten plus one or two turns.

If you want to know more, here's the link: http://www.lascofittings.com/threads


.
 
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