Acrylic joints....

[reefscapes]

I seem to have much trouble using the pins method. The pieces either move when the pins are removed or I do something lame that causes mis-alignment. The question is... Am I really short changing myself if the capillary method is used. I plan on building a rectangular calcium reactor and a 30L x 12W x 12H sump. Material to be used is .25 inch cell cast acrylic and Weld On #4.

I'd really love to hear from people who built their own sumps using the capillary method. Thanks all in advance.

Benjamin

[T Sandman]

What size pins are you using? How far into the joint are you inserting them? How long are you waiting to remove them? Have you been using weldon 4 exclusively so far? Are you positioning the pins to be pulled from the "inside of the joint or the "outside"? are you using weights to press the joint together once the pins are pulled?

I did a box this past weekend. I was a bit rusty but It worked. I was using weldon 3. I found that I did not wait long enough to pull the pins and I did'nt have enough weight on the panel to insure a good "squish bead" (non technical term). The only way to really get better at it is to keep practicing. I was pulling my pins after about 30-45 seconds. I think it would have been better to wait about 90 seconds or longer. once the plastic is viscous enough it should'nt migrate much during the "pull". I also found that the weight needs to be pretty substantial (I was using a full paint can) to push out the bubbles and get that good bead. You know you pulled too soon when the glue squishes out in little bubbles. And, weldon 4 takes longer to cure so it also would need more time to set before the pull.

Keep trying on some scrap. When you get a consistent, clear, bubble free joint with a good bead squirming out of the joint, you should feel confident enough to go ahead with your project.

Any other questions should be directed to the "acrylic fabrication questions, I can help" forum. Acrylics is the name of the member who is very informative answering most of the questions there.

Good luck

[reefscapes]

What size pins are you using?

Standard size pins that you buy from Savon with the small metal head. I sometimes hammer it down to prevent rolling.

How far into the joint are you inserting them?

Far enough that the pin protrudes to the other side of the acrylic.

How long are you waiting to remove them?

I'd say around 45 secs to a minute. All depends on the temp.

Have you been using weldon 4 exclusively so far?

Yes, WO #3 seems to set too fast for me. I need all the time I can get.

Pulling from outside or inside of joint?

Pulling from the outside. It's difficult enough to work from the outside of the box.

Are you using weights to press the joint together once the pins are pulled?

Yes and no. I can't use weights when initially setting up the sides. My process is to set the sides to the front panel first. I then use weights when setting the assembled sides and front panel to the back.

I'm not saying that the pins method do not work for me. I've actually done a few successfull projects with it. I'm just asking if capillary will work just as well for reactor and small sump projects. I seem to be much more consistent in bubble free joints with the capillary method.

I've wasted enough acrylic so I'm trying to figure out if I can successfully use the method that I am better at. Either way, DIY is much more fun but not necessarily cheaper:D .

[eric2524]

Originally posted by reefscapes
What size pins are you using?

Standard size pins that you buy from Savon with the small metal head. I sometimes hammer it down to prevent rolling.

How far into the joint are you inserting them?

Far enough that the pin protrudes to the other side of the acrylic.

.

You should use very tiny pis, some people use filded tin foil

The pins should not go all the way through to the other side, htey should go no more than half way, so the weldon can wick around the pins.

Your time to let it set up is good so is the temp.

[drock59]

So im thinking of building a sump and i need very clear directions of "the pins method." I have done several searches on this and find bits and peices but have yet to find a comprehensive outline of what to do. any help would be great.

[reefscapes]

CLICK (http://archive.reefcentral.com/forums/showthread.php?s=&threadid=169326&highlight=pins+method) on this for the DIY Pins Method by Zephrant. Can't get any better step by step instruction.

BTW, I've decided to stick with the pins method. My plastic supplier gives away 3x3 scrap acrylics to practice on. Finally got the hang of it and glad that I stuck with this method.

[drock59]

thanks a bunch

[werew]

take a look