Weld On 3 vs. Weld On 16 for Acrylic water leak

[Scorponok]

My acrylic tank is slowly leaking water at the bottom of tank. It seems like a few minor chips on its bottom side/edge is finally giving in.

Which acrylics solvent cement should I use? Weldon 3, the water type, or Weldon 16, the glue type?

Also, which type should I use for tank exterior, and which for interior? Since I have to drain the tank I might as well seal the inside too. Thanks.

Which to use?

 

[Clay]

Weld on 3 is very fast to dry, while 16 gives you more time to ply sheets together. What manner are you going to fix? Are you going to reseal the same pieces or add a patch?

I suggest adding a patch, and I suggest 16 for that.

 

[csnmusic02]

yea drain the tank use 3 than on top of that apply a layer of the 16, what ive always done when i get a new tank and im resealing it. and what I did when I built my 120 square.

 

[Scorponok]

Thanks both. Now I have the confidence to go ahead with the repair. I will try resealing it first, and if that doesn't work I will try patching it.

 

[hbluehunter]

yea drain the tank use 3 than on top of that apply a layer of the 16, what ive always done when i get a new tank and im resealing it.QUOTE]

X2, i usually seal the seam with the #3, and then a real thin coat of 16 to seal the deal..

 

[joey02]

3 sets WAY too fast... You'll have to be very experienced to use that stuff...

use weld-on 4.... still sets fast, but allows you to make small adjustments for about 20-30 seconds befor its too late.

Both are WATER thin.

16 is a much thicker cement. Like a thin syrop. Not easy to work with, but good to fill gaps.

Id personally use 16 to fix the leak.... 4 may cause some crazing... so dont go nuts with it near finnished edges.

 

[Scorponok]

Well guys. The reseal failed. The tank still leaks.

I just got some 1" x 1" acrylic square rods and I am going to use as patches on the inside of bottom edges. Will that work?

 

[Broski]

I've only done solvent welding for pressurized airtight vessels, but I'd imagine its identical.

Apply a line of weld on 3 on the two longer edges, now rest the bottom so its at an angle on one of the longer edges. lay it flat. once its set you should be able to put the weldon from the outside since the consistency is so thin. The weldon should fill all of the teeny tiny gaps. Once thats all done and set go out and buy some ABS or PVC cement (sold at hardware stores near the black ABS pipe). This is pretty similar, but it actually adds material to the bond. Go over all of bottom joints with it and let it set for a good 48 hours.

Solvent weld such as IPS weakens the material and removes mass on the bond, PVC/CPVC/ABS cement has added materials to strengthen the bond.