Properly sealing acrylic sump

[dafine20]

I built a sump to fit under my 30 gal. cube and thought everything was wonderful until it started LEAKING! I bought silicon from home depot and unloaded a tube and a half to put this thing together and the seals seemed pretty alright. A few days later I had a puddle all around the bottom.

Anything BETTER and quicker drying than silicon? Also, I did not use clamps because they cost 12 dollars for a 30 inch one and I would prefer not paying an extra 40 dollars if it's not necessary.

Any tips would be appreciated. I have a pin hole leak and I'll be sleep with one eye open tonight.

Thanks guys

[lllosingit]

You can't use silicone to put acrylic together, It won't hold.
Your supposed to use something like weldon, it actaully welds the pieces together.
I'll find a link for you

[dafine20]

Well damnit I feel pretty stupid for doing so then. Ya a brand name I can pick up at Home Depot would be appreciated. Looks like I know what I'm doing tomorrow night :o

[lllosingit]

here you go http://archive.reefcentral.com/forums/showthread.php?s=&threadid=96763&highlight=acrylicman
You might think about pulling the sump out of service until you get it fixed.
Silicone does not bond well enough to acrylic to handle the pressure and you may have a massive failure.

[lllosingit]

Originally posted by dafine20
Well damnit I feel pretty stupid for doing so then. Ya a brand name I can pick up at Home Depot would be appreciated. Looks like I know what I'm doing tomorrow night :o
Home depot may or may not carry weldon but if you have a local plastics shop they should have what you need.
I found mine under Plastics in my local yellow pages

[dafine20]

I read that thread (good info) So I'm looking for Weldon... is there a specific number I'm looking for. I think it was #3 possibly.

Also... How long after I apply the weldon can the water go back into the sump?

[serpentine5]

ok, I am by no way a pro when it comes to acrylic crafting. I have built a few things and through trial and error I can tell you a few things but I suggest you do a search for threads about building things out of acrylic so you can get a little education. First, all edges that are to be welded must be smooth and even. If you got the pieces from Home Depot pre cut on that score cutter they use, then i suggest you get the edges ran through a router or you can sand it down, but it wont give you the even edge you need. You can spend as much as two or three days just building it, and it must sit to cure for atleast 24 hours. I have experience with Weld-On #16 but from everything I have read #3 is a favorite. Depending on the size of this sump you are building, you might want to consider the "pins method" to put it all together (do a search for "Pins Method"). To tell you the truth, I am surprised that you only have a small pin hole in the seam and that the whole thing did not burst apart when you added water to it. You must have used a lot of silicone to bond it. You have two guys in here that really know their stuff, and they are great to get info from and dont mind helping some one out: Acrylicman and Zephrant. If you cant get Weld-on in your area, I know Home Depot does not have it, you can get it on line. This is where I got it:
http://www.tapplastics.com/shop/category.php?bid=21&
And I understand that if you use #3 you will need the bottles in this link:
http://www.tapplastics.com/shop/product.php?pid=170&
The tube of #16 I got there was less than $10 after shipping and I had it in less than 7 days.

[dafine20]

Appreciate the run down. When I used the silicone I used a lot of pressure when putting together the frame. I see the structure not so stabe now but it's doin pretttttyyyy good . It'll last me 24 hours :)

I cut all the pieces myself by scoring and then breaking the peices on the line I scored. The edges are crystal clear and smooth. They broke perfectly each time. That'll give me a good surface to bond. I read a little on the pin method. That is to remove air bubbles correct? I figured using clamps to squeeze pockets out would work too but never saw a thread about someone using them. Any reasons why?

As far as building. Seems like the Weldon becomes dry within a half hour or so. Does that allow me to continue to attach baffles and sections without worrying about it falling apart when moving the sump around or fliiping it?

Thanks for the crash course

[GatorCSM]

using the weld-on it is practically "set" within 1 minute to where you can manipulate the piece. That is using weld-on 4 though. I'm new to acrylic work, but I've liked using the 4 so far. It gives us people that are new at it a little time to correct our mistakes prior to commiting with our placement. That's only my opinion obviously, many people like 3, but that may be the more experienced ones... The first sump I made, I didn't get perfect seems with the weld-on and had 1 or 2 very small pin-hole leaks that would get a drop or two every minute, so I went ahead and used silicon sealant around all the seems just to be safe.

Good Luck,
Gator