Originally Posted by
kb0nly
I use Weld-On on acrylic all the time, perfect bond every time, not sure why your saying stay away from it. Silicone don't work for crap, i fought a fish tank for years that kept leaking over and over where it had silicone, the last time it was drained and cleaned applied some Weld-On 4 to the seam and thats been there for 5 years now, no more leaking every six months.
Silicone is ok for showers and tubs and sinks, and plumbers that can't cut a straight line, but its not a good adhesive for acrylic, to seal up a spot maybe, if you sand and prep the spot, even then the manufacturers i spoke with on the subject said that silicones adhesion rate to acrylic is a SURFACE BOND only. In other words put any pressure on it and its no better then a suction cup, it will fail at some point. Weld-On actually melts the two pieces together, you can do the same thing with MEK or even good quality acetone but the Weld-On is quicker to bond from my experience.
The tooth pattern idea i think is good because he wants a raised floor with the sides going down past, generally you would either have the floor supported by another structure to raise the tank or put in reinforcements like cross pieces under it. But i don't see silicone holding in that application because it would be lateral stress on the silicone with the weight of the water pushing outward on the sides, if it was only downward force then yes it would probably be ok but not as the primary fastening method for the sides.
Anyway, opinions are like bungholes, everyone has one, and thats my experiences and opinion on silicone and acrylic. Wrong glue for the wrong job. You also don't need to scrape the glossy edge to weld, i do it all the time, no issue.