Acrylic fabrication questions? I can help!

[Asp277]

Weld on 40 and bonding

Weld on 40 and bonding

Weld on 40 and bonding questions
Hey everyone. I'm new to site but have heard everyone is helpful. I just got several large pieces of 1" acrylic I am going to build a tank with. I have been reading through all the threads to find infonaut still had some questions.

1.) it seems like any one who does this well mixes there own formula of weld on 40. I've learned now that now shares that info, lol. But was hoping to find what raw ingredients it takes to make the 40. I would like to play with some mixtures.
2.) does changing the mix ratio make it stronger and can you screw it up to where it won't hold.
3.) how don you know if the mix is good or not?
4.) I read in some of the posts that one of the glue edges is cut at a slight angle. Does any one have the do's and don'ts of this or a pic? Also I read a thread of the pin method, can this be done with the weld 40?

Thanks so much guys. I know it's a lot of questions. I'm just really excited to learn. I have about a half dozen pieces of scrap to practice on first also.

Thanks

Eric

 

[Floyd R Turbo]

gpx1200, I think you can do rimless with 14" tall x 30" long, but it will probably need to be pretty thick or else it will bow quite a bit. Acrylics can chime in on this one but I'm guessing 3/4" minimum, probably 1" if you want to really reduce the bow.

Asp277, WO 40 is really no stronger than solvent welding for our purposes. Yes, the data sheets say it is stronger but if you read through this thread enough and find all the 'meaty' discussions on 40, what you will see is that a WO40 joint is only as good as it's fabricator, and you can screw them up. In fact, I remember Acrylics saying that he has seen more than one WO40 tank literally fall apart upon first fill. You can't tell if a 40 joint is good until you stress it, with a solvent joint you know right away. I think James/Acrylics uses solvent for up to 2.5" material, or somewhere around that thickness, so I would just stick with that for your 1" material.

I would strongly advise you to read through this entire thread - take the time - if you're going to make a large tank with large material. There are many factors to take into consideration.

As far as the 40 questions:

1) WO 40 comes in 2 parts, you just mix them together. There is no DIY wo-40. There is WO-42 which is WO-40 in a dispenser (like a caulking gun) and that doesn't require a centrifuge or vacuum system to get rid of bubbles.
2) it can, but I only know what I have read. Mainly you can increase or decrease the ratio and get a shorter or longer cure time.
3) you don't know until you make the joint and stress it.
4) I don't know.

 

[The Computer Ox]

Acrylic tank plumbing

Acrylic tank plumbing

I am upgrading from a nano tank to an acrylic SeaClear 46g, but have hit a snag on the plumbing. I have read much of this thread so I now understand a bit more about used acrylic tanks. However, with this tank not being drilled I have the choice of the plumbing to the sump. So far I have read about internal and external coast to coast, full height overflow in the rear center with a durso and lastly a bean animal overflow. I am really open to ideas.

also, I am working on polishing out the acrylic this weekend. I will post before and after pictures once I am done.

 

[Floyd R Turbo]

I am a fan of the BeanAnimal system. Simple enough to do, you can do it with an internal coast-to-coast and follow his plans for the plumbing outside the tank. It gets more complicated if you do an internal/external as the external really needs to be adhered to the tank properly, or you can also do that with bulkheads and avoid the potential detachment from the back of the tank. Just gotta make sure the external box, in whatever form, is solid. Drilling holes in acrylic is a piece of cake as long as you do it right.

 

[noobtothereef]

Het guys, ive got another acrylic question, i have a thermoformed acrylic truncated cone. Now since it has been thermoformed(vaccuum formed), will it craze when bonding? I can either use wo42 or wo4 which i have both of, will this piece need annealed first?

 

[The Computer Ox]

I am a fan of the BeanAnimal system. Simple enough to do, you can do it with an internal coast-to-coast and follow his plans for the plumbing outside the tank. It gets more complicated if you do an internal/external as the external really needs to be adhered to the tank properly, or you can also do that with bulkheads and avoid the potential detachment from the back of the tank. Just gotta make sure the external box, in whatever form, is solid. Drilling holes in acrylic is a piece of cake as long as you do it right.

Floyd, thanks for the response. I was leaning towards the BA system and after reading more about it I am going with it.

 

[Acrylics]

Het guys, ive got another acrylic question, i have a thermoformed acrylic truncated cone. Now since it has been thermoformed(vaccuum formed), will it craze when bonding? I can either use wo42 or wo4 which i have both of, will this piece need annealed first?

Annealing would be nice, but *shouldn't* be necessary. I glue a lot of formed pieces and don't have any issues.

James

 

[noobtothereef]

thanks for the info james, got another question for you, have you heard of ARKEMA G? My supplier has a stock of this at a really good price but i dont want to buy crap, i usually only buy polycast. FWIW my rep said it is made in mexico, could this be the same as plexiglass g?

 

[Acrylics]

thanks for the info james, got another question for you, have you heard of ARKEMA G? My supplier has a stock of this at a really good price but i dont want to buy crap, i usually only buy polycast. FWIW my rep said it is made in mexico, could this be the same as plexiglass g?

It's fine, Arkema makes Plexi-Glas and this should be the same

James

 

[Floyd R Turbo]

If it does not have print on the mask then it's the General Purpose grade of Plex-G. It's still cell cast just not up to tolerance. Read back a week or two I cover this a couple of times.

 

[noobtothereef]

I spoke with my rep again and they said its the exact same thing as plexiglass g, the reasoning for the cheaper price is its not a "spec" grade so they have less liability to sell it this way, and yes its a plain paper masking with no printing. Im not sure if the rep is blowing smoke up my bunghole or not...

 

[Floyd R Turbo]

Read this post of mine

http://www.reefcentral.com/forums/showpost.php?p=19471942&postcount=2333

 

[Floyd R Turbo]

Tank repair - possible?

Tank repair - possible?

I have a friend who got a nice big used tank with a nice big crack in it. I need to know if this is repairable, and also to verify my proposed method.

Here's the tank:

To start with, the tank is about 325 gallons, 72 L x 36 W x 29 H, all 3/4" (imperical) material (it's about 17-18mm so it's not Polycast).

You can see the problem in the above picture. The seam in the front right corner appears to have been bad from the start. There is a cloudy area along the bottom 1/3 of the joint, and from the top of that section upward is a crack through the front panel. Here are more pics (will have to split this into 2 posts):

Overall joint

Bottom, from front

From side

Middle from front

Middle from side

Top from front

Top from side

 

[Floyd R Turbo]

...continued

What it looks like to me was that the joint started to separate at the bottom, then a crack started and progressed all the way up the corner. No word when it appeared as it was in a wall, my guess is that the crack developed as the tank was being drained or removed. The previous/original owner claims the foggy joint was original and the fabricator claimed there 'must have been some dust that got into the joint'. Anyways...

The big problem is that it's not so simple of a repair. The fabricator (or someone) laminated 1/8" black acrylic to the inside of the sides and back wall of the tank, with what appears to be Weld-On #16, as you can tell from this picture

As as you can see again in this picture of the joint from the side

This panel does not fully contact the corner seam from top to bottom.

The tank will be built into a wall again, so this repair does not need to look pretty. My idea is to get a hold of a strip of thick acrylic, say 1" or greater, and about 6" wide, and the length of the inside height. The wide part would run along the inside of the side panel far enough to cross over the area of full adhesion of the weld-on 16 to the side panel which would transfer the stress properly across the joint. Otherwise, there's a weak spot around that bubble. I would set this gusset in place and bond it in with Weld-On 40 or 42.

The problem of the crack itself remains. If the load is released from the corner and transferred to the gusset, will the crack itself need to be repaired? Does this need to be done before adding the gusset in order to re-align the load on the corner and prevent damage to other parts of the tank? Also I think I need to stop the crack from progressing, it isn't all the way thorough to the top yet.

And....there is another crack. This one is in the back corner. The rear panel of the tank was notched at the corner like so

Which detaches the eurobrace from the back panel, completely, for about 12" on either end, and this appears to have resulted in another crack right where you would expect it

This crack is through the top euro and has progressed through the side panel. Again you can see there is the same issue with the black acrylic laminating job. An even larger gusset would be needed to take the stress off this corner I think.

So, James and anyone else, any advice??

 

[theshiver]

new tank

new tank

Hey all just have a question on a Acrylic Technor tank it is a 300gal 96x24x30and the seller said he thinks it is made out of 1/2 is this heavy enough or should I pass on it thanks

 

[Floyd R Turbo]

If you mean ten e cor then generally they build to the minimum but they use Polycast so as long as it has *no* cracks or anything, should be fine. remember - *NO* cracks. Examine every seam with a magnifying glass. Pay attention to the euro cutout corners. They don't always do a 2" radius unless the customer asks for it, they just make the euro wider.

Also if you get it, when you move it, make sure it's on a flat surface and preferrably foam and strapped down. Take a big bump in the van and even an empty tank can crack.

 

[dahenley]

a friend had a 300 gal 10x2x2 made of 1/2 and he had nice bowing in the front, and crazing on every seam from stress due to the thin material.

on a side note....
i heard that tenecooo is out of business....
the site is down, and the employees were sent home!!
phone numbers are turned off.......
(a friend of mine ordered a tank... and looks like he is getting burned....)


So.... dont expect warranty help...

 

[Floyd R Turbo]

Oh well, a substandard tank manufacturer bites the dust. I won't be shedding any tears. My LFS won't either after they screwed up their $25,000 1200 gallon tank and refused to fix it.

 

[noobtothereef]

yep, it sure doesnt look like $25,000 work on that tank....

 

[juststartingout]

Hi James,
I know that using a router table is the preferred method of routing acrylic but what about a larger piece, such as 96" x 36" at 3/4" thick, or 96" x 30" at 1" thick? I was thinking taht I could lay it out on the floor (over a piece of MDF or plywood, lay out my lines and make sure their square & then using a straight edge, route the piece of acrylic. Will this work & be as square or true as using a router table?
Thanks in advance for the advice,
Don (JSO)