reservoir crack repair-i have questions
 

hi all.this is my 1sy post here at this forum,as i thought this is where i could get the right advice.i use a 6x6x6,grey marine electrical conduit box as my res,see pic http://members.shaw.ca/rognjud/comp14.jpg.it has developed 3 cracks,2 by the bottom drain plug,and 1 by the pump outlet.these are brass fittings.curiously,the plastic 45degree barb shows no signs of cracks.is this a downfall to this type of container,or did i perhaps have the brass fittings torqued down too much.is this plastic not designed to have the walls of the container under that type of pressure caused by the tightening of the fittings.i epoxied last nite,the 3 cracks on the outside of the res.inside the res,i can see hairline cracks where the cracks are outside the res.is epoxy safe to use inside the res,which will come into contact with the water\antifreeze mix.also should i silicone over the epoxy,after it has dried,of course,both on the inside and outside of the res.thnx for your help

Might want to use the Plastic Welder version instead. But either way it should be fine. The Silicon is a good idea as the epoxy will wear down with the water.

i think it is safe to use silicone on your res however i would get all plastic fittings a brands new box with out crack. i would not rick my expencive components

thnx for replies.in talking to my dad,and brotherinlaw,i think what caused the problem was i tightened down the fittings too much.maybe ill just buy a new conduit box from home depot,and start over,but learning from my mistake.its only $17 canadian.thnx again

1. Replacing the cracked box w/ a non cracked box is the best repair.

2. Any time you are dealing with a crack, if you don't want the crack to continue to spread you should 'stop drill' at the END of each crack. This is when you take a drill (usually ~ 1/8") and drill a hole at the very end of the crack. This relieves the stress the crack is making and prevents it from spreading further. However this only works if you drill at the very end of the crack. (It is OK to fill the hole w/ sealant afterwards)

3. It is best to use plastic fittings in plastic holes, however you can use metal fittings if necessary. Just use lots of sealant and avoid excess torque as reccomended earlier.

4. The optimal glue for repairing (if you must, remember that replacing is better) is one that does solvent welding. Putting a layer of silicone over any repairs won't hurt, but ONLY if the stuff you are using has excellent adhesion to the box material, and if it is rated as suitable for constant water immersion. On any kind of glue, surface preparation is CRITICAL, follow manufacturers surface prep recomendations carefully.

Gooserider