RV Repair: fresh water tank repair, pool wall, lock nuts

Question
QUESTION: I have a 1998 21' Aerolite, with a 25 gal water fresh water tank.  It leaks where the nipple screws into the tank, in order to attach the hose to the water pump.  It appears the threads, in the tank a stripped.  I tried tape, but only slowed the leak. Will JB water weld work?  Where can I find a new tank, if needed.

ANSWER: New tanks are available online.  Discount websites are out there.  Just Google 'low cost RV or camper parts'.  

However, you can try other means first.  Make sure the tank is not cracked around the threads.  If so, a plastic repair epoxy rated for the type of plastic your tank is made of, at Home Depot should work.  If no crack, you can try a tap to clean out the threads, then a new nipple with plumbers putty on the threads, along with the teflon tape.  

Another idea is, find a nipple made to fit through the hole, but tightens on both sides with rubber washers.  The rubber washers will seal the tank, then you can put on fittings to make this fit your pump.  I know the fittings are likely 3/8" or so in size.  You might find something at a pool store that will work, but it may require you to make the hole bigger with a hole saw.  What I am refering to will be like the pump outlet hose attachment at the pool wall, to let the water back into the pool.  It pinches on both sides of the pool wall with lock nuts and rubber washers.  This is something you can probably build yourself at Home Depot, using full threaded nipple, washers, and lock nuts.  Just use galvanized, copper, stainless, or PVC parts.  Anything else will rust and ruin your tank of water.  

---------- FOLLOW-UP ----------

QUESTION: thank you for the advise.  The tank inlet is not cracked.  I don't know how to determine the type of plastic of which the tank is made.  The tank is a closed system; so, how does one insert a nipple with a rubber washer on the inside?  Will JB waterweld work to secure the nipple to the tank?  I guess that's my main question.

Answer
JB for plastic if you can find it will work.  An epoxy would too and is more common.  The epoxy you choose will tell you on the back if it will work with water tanks.  Also you want a type of material that won't matter if your water absorbs it and you drink it.  Maybe a CPVC glue at Home Depot.  That is 'safe' for drinking water.  Maybe you can find a fitting there that fits better.  I have found brass to fit better in plastic threads.  It seems to seal better.