weldon question

[mr pink floyd]

im building a DIY HOB fuge out of 1/4 acrylic, i have some resin bond(methalyne chloride), but its too thin to get a proper bond, and wont hold water. i want to use something thicker, which weldon would be good, ive heard alot about #4 and #16, but im not sure which is thicker... or maybe im wrong about those numbers, but which would be the best?


thanks,

Mike

[kgross]

The solvent being 2 thin is not your problem, you need to make sure your edges are perfectly flat before solvent bonding. To glue acrylic you use a solvent that will disolve the material and then when the solvent evaporates the two materials are mixed together into one piece. So you need the solvent to be thin to get into the joint.


You need to start out by reading these two threads
http://archive.reefcentral.com/forums/showthread.php?threadid=169326
http://archive.reefcentral.com/forums/showthread.php?threadid=562051

[mr pink floyd]

yea, ive doen a little acrylic work before, nothing that needed to eb water tight before, ive read the "pins" method

and im guessing its just the saw marks left from the table saw when the pieces were cut, so ill take some sandpaper and get them flat

thanks,

Mike

[kgross]

The other thing you can do is add solvent to the joint multiple times to keep all of th solvent from evaporating so you have more time for the solvent to work.

Kim

[BrokeColoReefer]

I have used weldon 3 with sucess with 1/4". as stated above, you need flat edges. I have used a jointer to get them perfect with out bubbles. Be carefull though, 3 is for cast acrylic, 5 is for extruded.

[Acrylics]

<a href=showthread.php?s=&postid=8509024#post8509024 target=_blank>Originally posted</a> by BrokeColoReefer
Be carefull though, 3 is for cast acrylic, 5 is for extruded.
BrokeColoReefer
Hmm, while you have no reason to believe me, please do disregard what "they" told you here - it's nonsense.
Use WO-3 for extruded as it sets up fast, *generally* too fast for cell cast.
Use WO-4 for either cell cast, continuous cast, or extruded.
Use WO-5 mainly for cell cast but will work for either. WO-5 contains acetic acid which will slow the chemical reaction down which is required for better bonds. The acid will also help make the solvent flow better so it doesn't "jump around", helpful in thicker acrylic. I know what IPS says regarding the use of some of their solvents but IMHO are quite simply wrong on some and this is an example.

The main problem with using the slower solvents (#4 & especially 5) for extruded acrylic is that they tend to dissolve too much acrylic and you get large ooze bubbles which just looks bad while providing no additional strength.

James

[BrokeColoReefer]

Good to know. I will take that advice. Im planning on using weldon 40 for my tank.

[mr pink floyd]

i could use a jointer, this is being done in my shop class, my teacher has a 40 gallon acrylic reef in the room(he didnt make it) but he has acrylic work expirence

tell me what tools would be best, ill try a jointer, ill use a table saw to cut, anything else?

[daytriper]

Use a roter tabel to cut it tabel saw chip to much.

[BrokeColoReefer]

i second that, the router and table are awesome for tuning edges. Got to have a good bit.