another giant tank construction - Page 3

cbui2 · #51 03/23/2007, 03:12 AM

hey nanoreef, my friend just built his tank 600gal and laid 6 layers thick woven fabric criss cross type with resin and this thing is solid definitely not going anywhere soon. matt what's new I started plumbing today probably take me another week or so to finished.

tank watch · #52 03/23/2007, 07:14 AM

Nano: thanks for the fiberglass tips. I was pondering the amount of fiberglass that would be necessary. Now I know that its "the more the merrier". More glass it is. Also, I have added pieces to the corners. I used 2x2 stock, ripped at a 45 degree to add the triagular pieces to the corners. I got that idea from dsandfort's thread. pics are somewhere in my cmera still.

Cbui2: not much lately. I am swamped with work, and will be for a while.
I scheduled a day with a friend to work on the tank, sanding, fiberglassing, and epoxy, but had to cancel for work. Its going slow. I'd like to see some of your plumbing though.

NanoReefWanabe · #53 03/23/2007, 10:31 AM

hehe well not so much more the merrier but...

the strength in fiberglass is derived from the fiberglass not the resin, i build lots of stuff out of fiberglass (bumpers, fenders, custom dashs, sub woofer boxes, kick panels, mostly car stuff but still) and i cant stress enough to have what little resin required to soak the fabric as possible..once the fabric goes translucent you have enough resin on it...

for a project this large you may want to buy a large roller to actually squueze the resin into the fabric and the excess out.

albeit; the resin is what is going to make this water proof/ tight. so it is a kinda a catch 22.

when building ove wood i like to coat the wood first with a nice layer of resin, allow it soak and get slighty tacky, then hang up my fabric, and applya a little more resin to soak it through..

and on another note, i dont know if it has been suggested to you for a reson or not, as i am not a structural engineer, but why did you choose fabric anyway? Woven fabric only has high strength properties across its strands therefore in only 2 directions. where a fiberglass matt has multidirectional strands providing far superior strength to that of woven. (though woven is far superior along the two directions) which leads me to believe you are more so fiberglassing for water tightness then you are strength, and for that purpose woven will be fine, you will have to acheive extra strngth some other way...i believe the larger tank builds i have watched used laminated pieces of 3/4 ply.

i assume woven was chosen for the 'neatness' factor...LOL if there is even one when doing fiberglass...it also will tend to lay out considerably smoother then mat over flat areas (other then at the edges, and that is where fiberglass mat excells) you may even want to employ mat for use in the corners, as it doesnt create seems when used properly thus eliminating mucho sanding...if you overlap two edges of fiberglass cloth (woven) you will get a nasty seem, especially with 6 oz (btw is that 6 oz/ sq foot or 6 oz/ sq meter/yard? two different measurement obviously the 6 oz/sq foot is considerably heavier) if you get fiberglass mat, you can tear it into pieces (considerably raising the mess factor) and thus eliminate any seems as the fryed edges will blend together and not leave any humps...

okay too much talking i am just going to sit back and watch this tank unfold now...

MORE PICS...

dsandfort · #54 03/23/2007, 11:20 AM

Just a note about fiberglassing. The first coat will leave a rough surface since the epoxy does not fill all the pockets in the glass weave (if you did it correctly). If you let this cure, it will need sanding before the next coat which will break up the weave strength since you will actually sand into the fiberglass. If you intend to put more fiberglass in the second coat, you need to do it before the first coat cures so the layers chemically bond. This is tough to do since the first coat will still be tacky.
That's why I went 1 coat fiberglass, 2 coats epoxy. That way, when I sanded, I only sanded epoxy and did not disrupt the fiberglass layer.

Just my thoughts.
Del

NanoReefWanabe · #55 03/23/2007, 01:15 PM

if your using epoxy resin there is really no need to sand inbetween coats...the reason people sand polyester based resin between cured coats is that as it cures it produces wax which settles to the surface...this wax will interfer the bonding process between layers. also sanding between coats is simply to remove the wax..not to shape the fiberglass, so it can be done with 200+ grit sand paper...there is also solents available to remove wax produced by resin.

resin without any sort of 'fabric' in it ill crack garuanteed, it is extremely brittle..but i do see where your coming from with sanding into the fabric though...mind you if the resin and material are applied correctly, when sanding you wont be able to distinguish between resin and fabric, i havent worked with 6 oz woven for a long time since i much prefer using chop mat but they are pretty much the same in that respect...

another thing i think it is important to point out is that fiberglassing the inside of the tank is mainly for water tightness not strength...large flat panels of fiberglass have basically no lateral strength to them and they will flex like crazy, basically adding no strength to the back bottom or side panels of a tank...because you are at most going to be appling 1/4 inch in total of fiberglass, more likely 3/16 though it is going to be fairly weak...would you want to bounce on your truck cap? or an uninstalled 3 piece shower? 600 gallons of water weighs ~5300 pounds i am only 180 pounds and if i stand on my truck cap it deflects..

anyway..

rppvt · #56 03/23/2007, 01:33 PM

Wait a minute--- I wanna bounce on your truck cap!
Seriously, it's posts like this that make RC what it is. There are a lot of guys who would be lost or leaking without this info. And it makes for fun dinner conversation.

dsandfort · #57 03/23/2007, 03:42 PM

My experience is only with West System, and it is limited to boats and skiffs and 1 aquarium which has yet to see water. But, I follow their technical advice and it works. If you are using West System, and I think Tank Watch is, there are several points to be made.

When you recoat, you must do it after the liquid phase of the base coat and before the cured phase. This is known as the gel phase. It's the phase when the epoxy is about as tacky as masking tape. At this time, additional coats will chemically bond. Once it reaches the cured stage, there will be an amine "blush" on the surface of cured product. This MUST be removed. It is water soluble and can be washed off with a scour pad and clean water, or by sanding. The point here is that there IS SURFACE CONTAMINATION on cured West System epoxy since it is an amine-based resin/hardner system.

Once the epoxy is cured, additional coats will not chemically bond with the cured product. The surface must be sanded to allow for a proper mechanical bond. West System recommends 80 grit to provide the proper "tooth" for the mechanical bond.

Bottom line, recoat during the gel phase or be prepared to sand between coats. And...I'd recommend reading up on West System technical and application bulletins.

tank watch · #58 03/23/2007, 07:08 PM

I am using the west system. Since I only have limited time slots available to work on the tank, the epoxy ends up curing before I can resume work. I am sanding between coats. I am glad you mentioned the fact that I will be sanding the fiberglass mat itself. I guess another layer will be needed.
I went with the woven mat because it came in the 6oz. which was recommended, whereas the chopped mat I only found in 1.5 oz. So far I only have a few strips of glass over the corners on the bottom of the tank. I did use a small roller to wet the wood then apply the mat, then pour on a little resin, squeegee, and pray. Some areas came out beautiful where the weave can clearly be defined, other areas came out thicker. Lots of sanding ahead...
My former neighbor has built a few small boats back in his day, and he offered to help me lay the glass. I want to do it all (glassing and 3 coats of epoxy) in one day so I dont have to do all that sanding. I just need a day off now.
Guys thanks for all the tips. I was using 120 grit paper, but I will step up to 80 grit. It clogs so fast, I switched to drywall sandpaper that is all mesh. Pics coming soon, need batteries for the camera....

cbui2 · #59 03/24/2007, 01:47 PM

hey Matt when we fiberglass custom boxes at the shop, my best method is laying matting flat on the floor in pc's you can work with, then soak the materials in resin of course not too much harder so you have time to play with it, then lay the materials down overlap all corners where strength is mostly needed. I would also use 2x4 around the perimeter just for extra support since so cheap, also add tons of support...lay it down as clean as possible to minimize sanding, IMO.

Tigger240 · #60 03/26/2007, 02:57 PM

i dont have experience with west systems, but messing with the resin / harderner ratios will mess with the curing process.

norskfisk · #61 03/26/2007, 03:51 PM

cbui2 is probably talking about polyester resin where you can vary the ratio since the hardener is only an accelerator that starts the reaction in the resin. With epoxy resin you must always use exactly specified ratios.

Using fiberglass on the outside of these tanks gives the needed stiffness. So 2x4 support is not needed.

norskfisk · #62 03/27/2007, 01:49 AM

NanoReefWanabe:
I have heard the oposite about the mat and cloth, cloth gives structural strength because of the long fibers and mat gives surface strength because of the multidirectional fibres. But it doesn't really matter because it is all strong enough for aquarium construction.
Very true what you said about structural strength of a thin layer of fiberglass laminate. But when you add it to the outside too it's like making an I beam out of that truck cap material. Then you have the stiffness.

I see a tendency that people use unreinforced layers of epoxy. I don't see the point in that really because the strength of a laminate comes from the fibers. Vacuum bagging, a modern technique used in composite construction, is all about getting as much fibers as possible per resin.

NanoReefWanabe · #63 03/28/2007, 11:03 AM

fair enough..i didnt realise you were glassing both sides...which i guess only makes sense incase of inevitable water spills etc...you would need all surfaces of the wood protected..

and yeah vacuum bagging squeezes out excess resin which does two things, it makes the piece superior in strength because it doesnt suffer from brittle ness of the resin and second and most importantly it reduces the wieght...

vacuum baggin also allows you to for around more complex shapes with one piece of cloth rather then have to cut it up, which destroys the strength found in uniform long fibers..

erics3000 · #64 04/19/2007, 04:22 PM

I still think a 2x4 and some bracing up top can t hurt. I have been planning on building a wooden tank viewable from both sides. Looks great so far any new pics?

cbui2 · #65 04/19/2007, 05:30 PM

ok matt you are long due for an update.

gwrulzmylife · #66 05/18/2007, 10:41 AM

sweet wood tank!

cbui2 · #67 05/18/2007, 11:23 AM

ok matt are you still around?

tank watch · #68 07/15/2007, 12:30 PM

Hi guys. Sorry I haven't been around. Summer is very busy for me at work. I will resume working on my tank soon. It has been on the back burner for a few months now.

tanya72806 · #69 07/15/2007, 08:52 PM

looks like your off to a great start

tank watch · #70 01/10/2008, 05:44 PM

Hey everyone. I am still at it and should have some pics in a few days.
I promised my wife a new kitchen for Christmas, so that had to come first as it was part of the design process for the new tank. Man, once you start something it can really snowball. A simple new cabinets and counter tops project turns into a new sheetrock, wiring, floor, ceiling, paint, cabinet and counter top project. Hope you guys are still tagging along...Matt

rppvt · #71 01/10/2008, 10:02 PM

Matt- I'm hiding this thread from my wife! If she knew she could get a new kitchen by just giving me a new tank, I'd have a delivery tomorrow!