Acrylic fabrication questions? I can help!
- Thread starter JohnL
- Start date
Floyd R Turbo
Either busy or sleeping
My experience is that wicking WO #3 or #4 into the gap will only do so much, because the gap is so tight that the solvent sets up nearly immediately and leaves air pockets. If you can actually force a bit more separation, you can avoid some of the air pockets. But any dust, water, etc that is in there will cause air pockets.
But, a few air pockets are better than one big honking air pocket. So the answer is yes, wick the solvent in, but either way you will still need a gusset on the inside to firm up that joint. No way around that.
But, a few air pockets are better than one big honking air pocket. So the answer is yes, wick the solvent in, but either way you will still need a gusset on the inside to firm up that joint. No way around that.
Thanks for your help. I have been reading about the tilt and pour method as well. With that spot being on the front panel would it be possible to pour on some weld on 40 and not use a gusset? What I'm thinking is cleaning out the area as best as I can and use some weld on 4, and then use the tilt and pour method on the entire front seam to seal it up the rest of the way and for some reinforcement. By the way the tank has been dry for a while so moisture shouldn't be a problem. Would injecting alcohol help clean it out?
Floyd R Turbo
Either busy or sleeping
You can try that, it's a decent plan (the WO40 idea). Some suggest to lightly scuff the area where the 40 will be poured so that it gets a little more "bite" into the surface, and that is Ok to do (the sanding/scuffing will go away when the 40 is poured on it)
It probably won't look pretty, but you're past that
For cleaning the crack, not sure. taking T-pins like are used for model airplane construction and pushing those into the crack (on both sides) just a tiny bit might open it up enough so that you can blow compressed air in there, the alcohol step is usually there to clean out any fingerprints or other residue, but salt etc might have gotten in there as well, so squirting alcohol then blowing it out (watch your eyes) might not be a bad idea. Denatured alcohol, not rubbing alcohol. Really though, watch your eyes...
It probably won't look pretty, but you're past that
For cleaning the crack, not sure. taking T-pins like are used for model airplane construction and pushing those into the crack (on both sides) just a tiny bit might open it up enough so that you can blow compressed air in there, the alcohol step is usually there to clean out any fingerprints or other residue, but salt etc might have gotten in there as well, so squirting alcohol then blowing it out (watch your eyes) might not be a bad idea. Denatured alcohol, not rubbing alcohol. Really though, watch your eyes...
Floyd R Turbo
Either busy or sleeping
you can use #3 or #4, or 40. 40 is probably the best but not totally necessary. With #4, you want it to be flush on both sides of the joint. Usually there is an area on the inside of the joint where the original solvent created a "fillet" and so you have to round off the corner so that the flat parts make contact with the front & bottom panel.
With 40, you don't need contact quite so much, if you take the same piece described above and pour in 40 then add the gusset and push it in tight, you will end up with a "dry joint" where the 40 has been pushed out. You could use the same gusset and then just not push it in fully flush with both panels. Or you could get a piece of triangle rod, which has a sort of built-in gap. It's hard to describe but the right-angle triangle rod isn't typically a true right-triangle profile, the 2 sides that are 90 degrees to each other are sort of "curved" and the tips are "flared" so that it stands off the front/bottom panels a bit, creating a void where the 40 fills in. I've used this on several repair jobs and it works extremely well
http://www.eplastics.com/Plastic/Plexiglass_Acrylic_Profiles/ACRTRI-LARGE
http://www.eplastics.com/Plastic/Plexiglass_Acrylic_Profiles/ACRRTTRI-500
You will probably want to call and verify that this is the case with this product. The reason they have the diagram on there now showing it is actually a right triangle is because I ordered a bunch of the equilateral stuff once when they didn't have it listed cleared as equilateral.
With 40, you don't need contact quite so much, if you take the same piece described above and pour in 40 then add the gusset and push it in tight, you will end up with a "dry joint" where the 40 has been pushed out. You could use the same gusset and then just not push it in fully flush with both panels. Or you could get a piece of triangle rod, which has a sort of built-in gap. It's hard to describe but the right-angle triangle rod isn't typically a true right-triangle profile, the 2 sides that are 90 degrees to each other are sort of "curved" and the tips are "flared" so that it stands off the front/bottom panels a bit, creating a void where the 40 fills in. I've used this on several repair jobs and it works extremely well
http://www.eplastics.com/Plastic/Plexiglass_Acrylic_Profiles/ACRTRI-LARGE
http://www.eplastics.com/Plastic/Plexiglass_Acrylic_Profiles/ACRRTTRI-500
You will probably want to call and verify that this is the case with this product. The reason they have the diagram on there now showing it is actually a right triangle is because I ordered a bunch of the equilateral stuff once when they didn't have it listed cleared as equilateral.
Floyd R Turbo
Either busy or sleeping
depends on the tank
Floyd R Turbo
Either busy or sleeping
Ugh. That's ugly. You can stop the gusset short of the corner. This is one of those that is gonna be tricky. First you have to clean the junk off with a vinegar soak, then clear out all those joints (if they end up with moisture in them, could take a while), then you're going to have multiple gussets meeting up in the corners, and the best way to do this is to pour them all at close times, so make one pour, let it set for 20 minutes, make the next, etc, tipping the tank one direction each time
Then there's the back seam that you cannot see...hope you got a deal on this tank
I would use the 1" gussets on this one. Tank looks like it might be underbuilt to begin with, and whatever is going on with the seams is indicative of a poor welding job, moving the tank too soon after setting the joint, improper support, poor quality material, or a combination of those.
Then there's the back seam that you cannot see...hope you got a deal on this tank
I would use the 1" gussets on this one. Tank looks like it might be underbuilt to begin with, and whatever is going on with the seams is indicative of a poor welding job, moving the tank too soon after setting the joint, improper support, poor quality material, or a combination of those.
Ok. Thanks again. I know where another tank similar to this one is that I might look into. This is the first acrylic tank that I've had, so I went into this sorta blind. I guess I know what to look for from now on. If I decide to fix this one, I'll post some pics and progress.
Scuba_Steve
Premium Member
I am trying to do my first edge preps. Please let me know how they look, and then maybe talk me through what I am doing wrong.
I am using a 1/2" Diablo template bit on a router table. Template is MDF.
This is really just a practice run to see how the edge looks. IMO, I still see cut marks, although they are very smooth. Much better than the saw cut edge. I tried a second pass and notice no difference.
Opinions/Advise?
I am using a 1/2" Diablo template bit on a router table. Template is MDF.
This is really just a practice run to see how the edge looks. IMO, I still see cut marks, although they are very smooth. Much better than the saw cut edge. I tried a second pass and notice no difference.
Opinions/Advise?
Floyd R Turbo
Either busy or sleeping
Those vertical lines are expected/typical when final routing. You're good
blackthunda77
New member
I'm sorry if this has been answered, I did a search on the thread but didn't find what I was looking for. Do you have a picture or a link on how to install and use a gusset. I have a tank that has a leaking seam and I might have to go that route.
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Sent from my SAMSUNG-SM-N920A using Tapatalk
Scuba_Steve
Premium Member
Thanks man!
Malign Reefer
New member
Which is typically used for acrylic tanks, Plexiglas G or Plexiglas GP ?
Floyd R Turbo
Either busy or sleeping
My brain feels rusty right now... Plex G is the good stuff, GM is (IIRC) the extruded stuff, GP I believe is what some distributors call the generic cell-cast stuff. This is also sometimes called PMACS, it is made by Arkema and has a plain brown paper mask (no markings) but it made at the same factory as Plex G, it is made to compete with other cheaper cast products. Basically, it is the same as Plex G but it maybe didn't pass certain quality checks like thickness consistency or clarity (flecks, surface imperfections, discoloration, etc)
Personally I've noticed no difference between Plex G and PMACS, and the warranty on G only covers a full sheet that has not been machined. So you would have to unmask the entire sheet to examine it, if it was fine, you would have to re-mask it before machining. If you found a flaw, you would have to be one of the few that buys $100K worth of their product a year in order to get paid for re-doing the tank.
That being said, a display tank should still be made with Plex G IMO. PMACS is perfectly fine for sumps and frag tanks, etc.
Personally I've noticed no difference between Plex G and PMACS, and the warranty on G only covers a full sheet that has not been machined. So you would have to unmask the entire sheet to examine it, if it was fine, you would have to re-mask it before machining. If you found a flaw, you would have to be one of the few that buys $100K worth of their product a year in order to get paid for re-doing the tank.
That being said, a display tank should still be made with Plex G IMO. PMACS is perfectly fine for sumps and frag tanks, etc.
Malign Reefer
New member
Thank you very much for the info.
We've had a coupla small displays sent back due to the flecks of "stuff" in PMACS back before I knew what it was so be aware, this is part of the program.
Plexiglass G and GM are the same thing, "MC" (melt calendar) is the extruded material. If you're seeing Plexiglass GP, it would be odd as Plex GP is the European version of Cyro/Evonik's Acrylite GP. Evonik owns the European rights to the name Plexiglass. Odd....
Probably 1.5". I've built tanks about that size but IIRC - a little smaller out of 1.25" so I'd "think" 1.5" should be fine
HTH,
James
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