Acrylic glueing

[dieden]

I am going to be making a 5 gal tank out of acrylic in the next couple of weeks and was wondering about the best way to bond them. I have seen numerous ways, but heard little about the pros and cons of the different methods. The bonding type I am most interested in is solvent bonding, as this seams to have the strongest final result. Is this too tricky to trust to a first time acrylic project? Would it be safer to stick to a silicon sealant?

If I choose to use solvent welding, what steps could I impliment to ensure the best possible result?

 

[lvsuckerfish]

for a 5 gallon tank you shouldn't have that many issues as you will want something to keep the tank square and pins to lift the sides from the bottom weldon 16 will work getting flawless seams will take more then one tank to accomplish. and an needle applicator from any plastic's store. a good person to ask would be Jason from CFI and or don W some other may chime in also.silicon will not work well for acrylic as bonding will have an issue. how or why I have no clue I stick to what I know and that is wrecked cars and estimates

 

[mcoomer]

Go to home depot and pick up some angle squares. These are plastic and you'll want to grind off the top corner that you see in the picture. Take the two acrylic sheets that you're trying to bond and put two squares on the inside and two on the outside to set your angle. You're going to need to clamp your work in place but not so tightly that it can't move. If the clamps are too tight your acrylic sheets won't be able to slide into place when you apply solvent. For a smaller project like a 5 gallon tank you can probably get away with using blue painters tape to hold your sheets and angle squares in place. Slide some straight stick pins into the seam to provide a slight separation so that the solvent can penetrate. With the pins in place, doublecheck that your pieces are square and get ready to apply your solvent.

Fill a needle applicator with solvent. I prefer water thin solvent over the thicker Weld On 16 but either one will do the job. Put the tip of the needle at the end of the seam and pull it towards you and down the entire length of the seam. You'll have to pick up the applicator and reapply it to get around the angle squares but with the corner ground off you can get the needle under it to apply solvent to the entire seam. Having the corners ground off will also keep the squares from contacting the solvent and bonding to the pieces that you're working with. Once you're solvent is in place, gently pull the stick pins out and allow the acrylic to settle in place. The solvent will work its magic and you'll have your tank built in no time.

When you get your acrylic, buy a few extra small pieces and practice. Figure out what you need to do to clamp the work in place so that it's stable but can move enough to settle into place on the solvent. The preparation is the tricky part. Getting everything in position so that it falls into place is critical. Applying the solvent is the easy part.

Practice before you start and good luck.

Mike

 

[DonW]

Looks like you got some pretty good advice. There used to be some short video's on tap plastics web site. Stay away from 16 it has its use but not tank building. Weldon #3 is the water thin stuff and will work for a tiny tank. Weldon #40 is the good stuff and really what I'd use for any tank. Remember you need cast acrylic.

Don

 

[dieden]

So shy away from extruded.. Any particular reason?

 

[DonW]

So shy away from extruded.. Any particular reason?

Ive heard it absorbs water. But it will work for a short while, the joints will fall apart and the tank will explode. You need to go with cast. Besides it not much more money. Besides its easier to machine and tougher to scratch.

Don

 

[Herefishyfishy]

Ive heard it absorbs water. But it will work for a short while, the joints will fall apart and the tank will explode. You need to go with cast. Besides it not much more money. Besides its easier to machine and tougher to scratch.

Don

WOW Don, sooo much said in sooo few words.
This post of yours and Mcoomer's should be a sticky somewhere, seriously!

 

[dieden]

Exploding tanks=bad cast acrylic it is 

 

[mcoomer]

The only sticky I want is a gallon of honey and an hour with Eva Mendes but thanks for the thought.

As Don said, get cast acrylic. Extruded acrylic will absorb water and expand. Also, when you're working with your acrylic sheets, only peel away enough paper to reveal the sections you're trying to join. Leave as much paper in place as you can to protect against drips and scratches. When you get ready to place the tank on your stand, pull the paper on the bottom and take the rest off once you're sure that everything's in place the way you want it.

Mike

 

[DonW]

This was the first tank I built. Look great! But the seems failed after about a year. It was extruded but just leaked and was tore down prior to exploding.

 

[Scooterman]

This was the first tank I built. Look great! But the seems failed after about a year. It was extruded but just leaked and was tore down prior to exploding.

That's a nice looking tank, I bet you've come a long way when it comes to gluing acrylic!

 

[dieden]

Well I picked up the acrylic, 1/4 inch black for the bottom and overflow and 3/8 inch clear for everything else. Does anyone know a good way to polish the cut edges?

 

[DonW]

Well I picked up the acrylic, 1/4 inch black for the bottom and overflow and 3/8 inch clear for everything else. Does anyone know a good way to polish the cut edges?

Dont polish until its built except for maybe the overflow. You need sand paper to polish it. Go down to about 3000 then move to rubbing compound. Plain old cheap turtle wax rubbing compound is perfect on acrylic. No flame polishing near a joint.

Don

 

[dieden]

I am a little worried about trying the Weldon #40 due to it being a two part. Would Weldon 3 be strong enough to last on this project? I know you said #40 is better grade stuff, but it seams a bit more complicated.

 

[DonW]

I am a little worried about trying the Weldon #40 due to it being a two part. Would Weldon 3 be strong enough to last on this project? I know you said #40 is better grade stuff, but it seams a bit more complicated.

3 is fine for such a small tank.

Don

 

[Guerry]

I perfer Weldon#4 make sure you have good straight cuts then use scaper to clean any saw marks out (3 is a faster cure time
) here's pic of how I prepair edges