rotomold tank repair?
- Thread starter Bob J.
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Not very likely
Would this happen to be an object lesson in why it's important to make sure the holding tank vent never becomes blocked?
'Cuz the stress that caused it to crack in the first place will also pull the weld apart. So if it's a waste holding tank, don't even try. But if it's a water tank and the crack is on the top, it MIGHT be worth trying depending on the cost. Just dribbling P-tex into it won't hold though...it has to heat welded to have a prayer.
Would this happen to be an object lesson in why it's important to make sure the holding tank vent never becomes blocked?
I was hoping you'd chime in Peggie. The crack is at the outlet so I think doing dock side pumps out caused the crack due to excessive vacuum/blocked vent. I had read an article that discussed tank repairs by gas welding & your comment on "heat welded" just confirmed that. I'm going to give it a shot, got nothing to lose.
Thanks!
Thanks!
1. how big is the crack? if it is small enough drill out and have a fitting installed in it you may purchase a bulkhead fitting and a pipe plug amd repaire it that way
2. is it a water tank or holding tank? if it is a water tank it is woth a try but if holding tank scuttle i5t and replace it with new
3. is the crack on top? that would be a big plus if you can find a tank company close to you that welds tank fittings in plastic tanks.....
the cost of shipping a long way off is sooooo cuonter productive it would be better to just order a new one and pay freight only one way
regards
woody
Yes it is possible to repair rotomolded. Some tank builders who specialize in industrial Poly tanks can weld the crack using a fiberglass 'scrim' to polyethylene 'overlay' ... and affect a 'patch' (similar to a ski shop who can repair torn ski bottoms). Such repairs usually can only be performed on tank sections that are not 'fully stressed'. So, if you live in an area that has a high population of 'chemical plants', pharmaceutical, etc. plants then seek out one of these 'builders' ... but its not going to be 'inexpensive'.
FWIW - I 'believe' that 3M has recently developed an adhesive/glue suitable for 'minor' repairs on polyethylene. You might want to do a websearch of 'industrial suppliers' - Grainger, etc..
examples: http://solutions.3m.com/wps/portal/...JJ60IS8FSO6Q3GD3_nid=P1LTGPF01Gbe7ZMZSJBQRHgl ,,,, and ... http://solutions.3m.com/wps/portal/...E3E02LECFTDQGLE0_nid=NSSR7S8QPKbeW8LNFLFN3Xgl
FWIW - I 'believe' that 3M has recently developed an adhesive/glue suitable for 'minor' repairs on polyethylene. You might want to do a websearch of 'industrial suppliers' - Grainger, etc..
examples: http://solutions.3m.com/wps/portal/...JJ60IS8FSO6Q3GD3_nid=P1LTGPF01Gbe7ZMZSJBQRHgl ,,,, and ... http://solutions.3m.com/wps/portal/...E3E02LECFTDQGLE0_nid=NSSR7S8QPKbeW8LNFLFN3Xgl
A tip I was taught many years ago was to drill a small hole at the ends of the crack before attempting the repair. The intent was to prevent the crack from migrating further.
All of y'all are overlooking one thing:
There may be tank fabricators who'll work on a USED waste holding tank, but in more than 25 years, I've yet to find one. UPS may not even accept it for shipping.
Only two things can crack the female threaded "collar" in the tank...
1. over-tightening the thread-barb fitting. They're self sealing and should only be tightened ONE turn past hand tight, even if most of the threads are still showing. 2. Using a straight thread-barb fitting where a 90 is needed. The hose pulls on one side of the fitting, putting enough stress on the spinweld till it breaks the weld.
Closing up that fitting and installing a new one won't work 'cuz there's no way to seal up the cracked fitting other than knocking it out and spin welding a new one in.
You're actually seriously considering trying to mend a cracked DISCHARGE fitting in a waste holding tank? Surely, not one that's at the bottom of the tank...???
Do you have the tool to heat weld poly? 'Cuz it's not the same thing as just dribbling P-tex into a ski bottom. A heat welder simultaneously melts the edges of the crack while also injecting new melted poly, so that it all runs together to become a single mass. And you'll need a clamp to keep 'em together till they cool and harden. But then you'll no longer have a threaded fitting, so how ya gonna get a thread-barb fitting back into the tank?
IMO the only good answer is: bite the bullet and replace the tank. Ronco Plastics is your best source Ronco Plastics They make TOP quality tanks for a very reasonable price (which is even more reasonable if you order it through the online store at this site) and have more than 400 shapes/sizes, including over 100 non-rectangular...and they install fittings in the sizes and locations specified by the customer when they make the tank.
There may be tank fabricators who'll work on a USED waste holding tank, but in more than 25 years, I've yet to find one. UPS may not even accept it for shipping.
Only two things can crack the female threaded "collar" in the tank...
1. over-tightening the thread-barb fitting. They're self sealing and should only be tightened ONE turn past hand tight, even if most of the threads are still showing. 2. Using a straight thread-barb fitting where a 90 is needed. The hose pulls on one side of the fitting, putting enough stress on the spinweld till it breaks the weld.
Closing up that fitting and installing a new one won't work 'cuz there's no way to seal up the cracked fitting other than knocking it out and spin welding a new one in.
You're actually seriously considering trying to mend a cracked DISCHARGE fitting in a waste holding tank? Surely, not one that's at the bottom of the tank...???
Do you have the tool to heat weld poly? 'Cuz it's not the same thing as just dribbling P-tex into a ski bottom. A heat welder simultaneously melts the edges of the crack while also injecting new melted poly, so that it all runs together to become a single mass. And you'll need a clamp to keep 'em together till they cool and harden. But then you'll no longer have a threaded fitting, so how ya gonna get a thread-barb fitting back into the tank?
IMO the only good answer is: bite the bullet and replace the tank. Ronco Plastics is your best source Ronco Plastics They make TOP quality tanks for a very reasonable price (which is even more reasonable if you order it through the online store at this site) and have more than 400 shapes/sizes, including over 100 non-rectangular...and they install fittings in the sizes and locations specified by the customer when they make the tank.
I did a small crack patch (windshield washer and a Jeep radiator expansion tank) using a soldering gun. I cut a deep 1/8 inch "V" along the crack and carefully melt the filler material into the "V" gap. I melt extra material on top of the gap to strengthen the area. It held even under nominal 15-20psi pressure. Didn't try higher pressure.
Again, you have nothing to loose.
Again, you have nothing to loose.
>You're actually seriously considering trying to mend a cracked DISCHARGE fitting in a >waste holding tank? Surely, not one that's at the bottom of the tank...???
That's one of the good things about being in the mechanical contracting/engineering business, we come up with some pretty fubar ideas but we do have all the great tools to execute those ideas
Yea, it's the fitting at the bottom of the tank. It has cracked the threadolet portion & the crack has extended on both sides of the "weld". I'm not going into this trying to save the cost of a new holding tank. After your comment about heat welding now I just want to see if it will work.
Thanks to all for the advice!
Bob
That's one of the good things about being in the mechanical contracting/engineering business, we come up with some pretty fubar ideas but we do have all the great tools to execute those ideas
Yea, it's the fitting at the bottom of the tank. It has cracked the threadolet portion & the crack has extended on both sides of the "weld". I'm not going into this trying to save the cost of a new holding tank. After your comment about heat welding now I just want to see if it will work.
Thanks to all for the advice!
Bob
Plus One for RONCO
Bob,
When I replaced our original Ronco holding tank with a larger one, I had them change the fittings so that all were on top. The original tank had separate bottom threaded outlets for deck pump out and thruhull pump out (in legal areas).
I did not like the idea of any fitting that might potentially leak out, and the rep at Ronco told me that they spin-weld in those fittings either way and some customers want bottom and some top.
The top-type uses a tube that goes down to the bottom with a angle-cut for the end. Very solidly engineered. I had them put in two of these "dip tubes" and the one entry fitting, plus a threaded clean out. It's a thick wall tank and should out last all of us.
(Heck, I later cleaned up and sold the original tank to another boater for a few bucks.)
They are a good company. When you fax or email your new tank diagram to them, be sure to accurately indicate where the fittings and the all-important clean out port goes.
LB
Bob,
When I replaced our original Ronco holding tank with a larger one, I had them change the fittings so that all were on top. The original tank had separate bottom threaded outlets for deck pump out and thruhull pump out (in legal areas).
I did not like the idea of any fitting that might potentially leak out, and the rep at Ronco told me that they spin-weld in those fittings either way and some customers want bottom and some top.
The top-type uses a tube that goes down to the bottom with a angle-cut for the end. Very solidly engineered. I had them put in two of these "dip tubes" and the one entry fitting, plus a threaded clean out. It's a thick wall tank and should out last all of us.
(Heck, I later cleaned up and sold the original tank to another boater for a few bucks.)
They are a good company. When you fax or email your new tank diagram to them, be sure to accurately indicate where the fittings and the all-important clean out port goes.
LB
We offer Ronco tanks at a discount here, give me a call 9-5 Pacific if you end up needing a new one
Hey Dave,
Peggie had mentioned that once before so after I play w/ this tank repair, bottom line is I'll be contacting you for a couple of new tanks. Even if we are able to fix the holding tank, after 31 years in the boat & sitting outdoors all summer it still has a lovely aroma that would make a pig farmer blush.
Peggie had mentioned that once before so after I play w/ this tank repair, bottom line is I'll be contacting you for a couple of new tanks. Even if we are able to fix the holding tank, after 31 years in the boat & sitting outdoors all summer it still has a lovely aroma that would make a pig farmer blush.
Bob:
Here is the Ronco catalogue so you can find a tank that is suitable for your application. Ronco will place the fitting where ever you need them. I have found that SBO has equal or better prices on most item and their service is great.
http://ronco-plastics.com/
Here is the Ronco catalogue so you can find a tank that is suitable for your application. Ronco will place the fitting where ever you need them. I have found that SBO has equal or better prices on most item and their service is great.
http://ronco-plastics.com/
Replace your Ronco bookmark, Steve...
That one hasn't worked for years...the one that I posted above is right one and goes directly to their marine tanks catalog: Ronco Plastics
Bob, plastic tanks don't permeate...all that lovely aroma is actually coming from INSIDE the tank. Clean it off and put threaded plugs in all the fittings and it'll cease to be any competition to the local pig farmer. However, hoses DO permeate...we haven't discussed those yet.
I'm 90% certain that Kracor made your existing tank. You can get a replacement from them, but only for an outrageous price (about $500 I think), with NO choice as to fittings sizes and locations. So let's try hard to find a Ronco tank that'll fit.
Btw...are you on the sabre email list? If not, you should be 'cuz they're a really great group!
That one hasn't worked for years...the one that I posted above is right one and goes directly to their marine tanks catalog: Ronco Plastics
Bob, plastic tanks don't permeate...all that lovely aroma is actually coming from INSIDE the tank. Clean it off and put threaded plugs in all the fittings and it'll cease to be any competition to the local pig farmer. However, hoses DO permeate...we haven't discussed those yet.
I'm 90% certain that Kracor made your existing tank. You can get a replacement from them, but only for an outrageous price (about $500 I think), with NO choice as to fittings sizes and locations. So let's try hard to find a Ronco tank that'll fit.
Btw...are you on the sabre email list? If not, you should be 'cuz they're a really great group!
Thanks for the links, had downloaded the Ronco catalog awhile back. The tank in the boat is a 20 gallon Kracor & less shipping it's $525.00 An equivelent Ronco tank with the diminsions that fit in the space is 18 gallons & can be had for around $250.00
I'm on the Sabre email list, lot's of good info.
Have a great weekend everyone!
I'm on the Sabre email list, lot's of good info.
Have a great weekend everyone!
Well here's the story on attempting to do the tank repair.
We were able to fix the crack & replace the fitting. It wasn't too difficult but I wasn't the one on the stinger. We air test the tank at the shop, we're good to go. So, I get the tank home decided to fill it up with water & a little bleach to really sanitize it before putting it back in the boat. The tank is standing on end, our dog sees the tank, starts barking like hell, vaults off the porch, tackles the tank which falls over with a thud & the side of the tank opposite the repair blows out in 2 pieces.
After that I decided to sanitize myself & pour another Jack Daniels.... LOL
We were able to fix the crack & replace the fitting. It wasn't too difficult but I wasn't the one on the stinger. We air test the tank at the shop, we're good to go. So, I get the tank home decided to fill it up with water & a little bleach to really sanitize it before putting it back in the boat. The tank is standing on end, our dog sees the tank, starts barking like hell, vaults off the porch, tackles the tank which falls over with a thud & the side of the tank opposite the repair blows out in 2 pieces.
After that I decided to sanitize myself & pour another Jack Daniels.... LOL
3 M makes a polyethylene "weld" compound that works very well. We repaired the poly tank (for water) that had a pressure crack, It's not had a problem in 3 years. The crack was caused from pressure build due to a blocked vent tube.
http://www.shop3m.com/62449526318.html
This is what we used
http://www.shop3m.com/3m-scotch-weld-plastic-adhesive-dp8010-xdqktrgpf1.html
http://www.shop3m.com/62449526318.html
This is what we used
http://www.shop3m.com/3m-scotch-weld-plastic-adhesive-dp8010-xdqktrgpf1.html
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