Floyd R Turbo
Either busy or sleeping
James,
I've been working on a tank made of 3/4" Plex-G. We set the vertical joints with little issue. The top euro looked good except for right at the joints of the vertical panels in each corner where I forgot to scrape off the little bit of solvent that goos out when you pull the pins and then adjust the panels to be flush (oops). It's not horrible, but quite a few small bubbles right there on the corners. Much to worry about? Top is 1/2".
But, this is the real reason for my post below. We set the bottom joint and bubbles seemed to 'form' in a few spots as we ran the solvent in. As we filled it, the joint looked good and filled, then the bubbles would just form almost out of nowhere. Here's a few pictures. Tell me if this is really anything to worry about:
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The tank is 48 x 19 x 30 H, 3/4 walls, 1/2 top/bottom, euro has 2.5" perimeter w/6" center, 2.5" radius corners. Used pins method, wiped both panels with denatured alcohol, blew off with air compressor, then canned air after pins, joint was still wet when be pulled the pins too so there was a nice fillet all around. Solvent was straight MC w/5% to 6% AA.
The only thing I can think of is maybe we should have shimmed the pins a little more aggressively all around to get them really tight. We really only needed to shim the corners and a little on the ends - table is a little crowned in the middle (maybe 1/8" higher), but the double-sided foam MDF boards seem to take care of a lot of that. Also I had one bad bubble (second pic) that seemed like the solvent didn't want to fill in, it was filling in at the inside and outside edges like a "U" then the solvent closed in around it making the bubble. Strangely this was over the crown in the table.
Could this be dust particles? I have noticed that it's kind of hard to clean the edges perfectly because of static. Even after wiping with alcohol and compressed air and canned air, I can't always get all the dust off. Is there a trick?
Is this joint doomed, or just unsightly?
Being the largest thing I've built to date, I am discovering that I may need to make some modifications to my table or technique, or both. I hope you can shed a little light on this...thanks in advance.
EDIT: PS the bubbles in Pic #3 are elongated because the joint floated after we pulled the pins, and we noticed it just in time to re-adjust it...
Bump on this one...could really use an opinion James...
Another thing we noticed today before drilling the holes was that the inside corner of the back bottom seam didn't have much of a fillet. If you look down along it, right in the middle for about 6 or 12 inches, it's almost non existent, or 'beaded' where you can see little bumps or dried solvent/acrylic, but the gusset isn't continuous. I think we were so concerned about the bubble in Pic #3 and aligning the tank after it floated that we check and go over the inside seams. There were no bubbles pulled into the seams near the area of the lack of fillet, but with this in combination with the bubble in pic #3, do we pretty much have to add a gusset along the back joint, just to be safe? Or just run over the seam with WO40 or even WO16?
Guess I'm still on the learning curve. Plenty of work with 3/8" and I can make seams that look like glass with beautiful fillets. So this is making me a bit nervous.