Photo tank instructional

I’ve been asked several times to explain how I build photo tanks. I hope this topic will accurately describe how I’m constructing them. I should explain that I don’t believe this is the best way to make small acrylic tanks, in fact I believe the use of a table saw and router could easily cut your time in half, reduce or even eliminate the need for sanding and assure perfectly square pieces of acrylic. This method will only require very inexpensive tools/equipment allowing just about everyone to build a tank of their own.

Materials list: IPS “weld on #4” welding solvent, glue applicator, small jigsaw, fine tooth blade for jigsaw, sanding block, medium, fine, and extra fine sandpaper, masking tape, tee square and suitable sized ¼” acrylic sheet. A few notes on material that I feel are worthy of mention: Most local hardware stores will offer to cut the acrylic for you. It will cost more for pre-cut pieces but can save you a lot of trouble and time. Make sure the acrylic has its protective film intact since any imperfections in the film will allow the solvent to ruin the finish. I like acrylic with paper backed protective film since it holds up to this process much better than plastic film alone. It’s very important to use a jigsaw blade with the most number of teeth possible for an uneventful cut. Additional sandpaper with a finer grit (as fine as 600) can be used for a polished look on the edges.

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Design/layout: Much of this step is personal preference but I can tell you what I like and why. I most commonly use a tank that’s 12” wide, 6” water depth by 4”. This tank size when used with a paddle will allow you photo the tiniest fish as well as sunfish and Esox up to 11”. It’s important to know what the actual thickness of the acrylic is before your final design is implemented. Most ¼” acrylic is roughly .22” (not .25”). This discrepancy isn’t of major importance but it will affect the bottom plate dimension and you’re likely to have it slightly oversized if you’re not careful. If you think of the sides of the tank as identical pairs, you’ll eliminate leaks and assure a proper fit. For this reason make sure and lay out your lines to cut the pieces as shown to assure the widths are identical. Please remember to handle your backing carefully and never remove the backing. This is the only thing preventing the welding solvent from damaging the acrylic.

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Cutting: I simply mark the paper when I use paper backed acrylic. I use masking tape on the areas I will make cuts when I use the plastic film backed acrylic. It’s most important that your marks/cuts are perfectly square since the pieces will be of no use unless true. Slight errors in dimension can be fixed but pieces that aren’t square can force you to spend much time reworking the pieces. A square is a must for marking your lines. When cutting, I place the acrylic on the edge of a table and hold it firmly. I make sure and have the line I’m cutting less than an inch from the table edge to prevent flex and binding the saw blade. When cutting make sure and not deviate from the mark since this will create much work for you when sanding your edges. Don’t force your saw to cut quickly (watch your feed rate) as this tends to cause you to deviate from the marks as well as heat the acrylic enough to melt it. When finishing a cut, be careful to not allow your piece to drop or chip either corner. Corner damage will either create leaks or lots of sanding work. If you make a mistake, it’s not the end. In the next step you’ll be able to inspect the accuracy of cuts and fix some errors.

Sanding: If this is your first tank, it might be a good idea to see how your pieces fit in case you’ve made an error that can’t be easily remedied. If the pieces generally fit well, I place a piece on the edge of the table just as when they were to be cut. I use 100 grit paper and sand about 10 strokes and look at the edge. If cut well, the edge will not have deep saw marks. It’s critical to sand gently, apply even pressure, use full strokes, hold your sanding block exactly perpendicular to the piece, and never round the corners. Continue to sand all edges until your saw marks are gone. I usually count strokes and make sure I apply a similar number of strokes to opposite edges (remember your pieces must be paired or exact copies on the width dimension). This is a good time to mention you get one free mistake edge. This is the edge that will later be the top of the tank. Since you will not be welding anything to this part, it’s not important to have a perfect edge. Identify your problem cut and make this your top. Once the edges look good, assemble the tank (you can use masking tape to hold the pieces together) and inspect for rounded corners and oversize pieces. Make corrections and move to 150 grit paper or similar. Sand in the same fashion as with the 100 grit paper until you see the marks from the 100 grit paper disappear. All edges must be done in this way and 50 strokes or less will often get the job done. Now repeat with 220 grit and feel free to move onto 400 and then 600 grit but 220 will be suitable for welding. Please pay particular attention to the smallest piece (ends) as they have three edges that are welded. The ends are by far the most critical piece.

Inspection: Now you should inspect your edges and decide where you want to place them depending on quality. It’s a good idea to at least mark the top and the outside with permanent marker. Once marked, clean the piece then assemble your tank with tape and very closely inspect all edges for good contact. It’s important to understand the welding solvent is water thin and isn’t glue. I presume it reacts with acrylic and bonds parts that are in contact. If your pieces aren’t properly fit, you will not bond and most certainly leak. If the pieces aren’t contacting well, identify the issue and sand until they fit. It’s possible to use the glue applicator and apply water to your contact areas to be sure they contact well.

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Film removal: With all of your pieces inspected and marked, you can remove the protective film in the specific area that will be welded. With the tank disassembled, mark the areas you need to remove the film. Remember, you need to have the acrylic contact acrylic and not the film or any other debris. I use a very sharp razor and gently use the razor perpendicular to the acrylic. When done properly, this mark will be all but invisible. Since you’re using a razor on acrylic, you will leave a mark. Please be careful and cut closely to the required mark so the cut will be out of the area that you’ll be photographing fish. Remember, any exposed acrylic will be damaged by the solvent. Now gently remove the narrow strips of film.

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Final assembly: Make sure the pieces and work area are impeccably cleaned before final assembly. I use liquid dish soap and warm water on the pieces to remove all of the dust, shavings and abrasive remnants from the sandpaper. Your pieces must be free of water prior to welding so letting them dry overnight is a good idea. Have plenty of narrow strips of masking tape handy and put your tank together. Use enough tape to secure all pieces and pay particular attention to the corners. Inspect again and make sure all edges make good contact with acrylic. This is your last chance to correct any errors.

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Welding: When using the welding solvent, please remember it’s as this as water and you can only apply solvent to contact points that are on the horizontal plain. I always place the tank on its bottom and weld the bottom to the sides first. I usually recheck all of the fits and then fill the glue applicator with about a half teaspoon of welding solvent (make sure the work area is well ventilated when using the solvent). A little solvent goes a long way (a 4 oz. bottle will make dozens of tanks) so no need to fill the glue applicator with more than you need. The solvent can be applied from either the outside of the tank or the inside. The joints will draw the solvent in and fill the slight air gap. Work the glue applicator quickly to fill the gaps but try to avoid working too quickly as this might cause you to miss areas. Some solvent will be dawn up the side contact areas and this should not concern you but don’t try and fill all of the air gaps at once. Quickly inspect the bottom contact areas and add solvent where needed (you might have to apply a little solvent here and there from the opposite side that you originally placed the solvent). If all looks good I wipe up any excess solvent and place a book or similar object of moderate weight atop a folded bath towel. The bath towel helps evenly distribute the weight to all parts of the sides. Make sure and not disturb the tank in any way once you apply the solvent. Allow the tank to cure for a few hours minimum (I usually wait overnight) and place the tank on it’s side (again make sure and only apply solvent to the horizontal plain). Apply the solvent as before, wipe us excess and use the book and bath towel. Allow to cure and weld the last side. If you’ve complete all welding in one day, make sure and allow to cure overnight at a minimum. Please remember this instruction is specific to a tank of this size. Larger tanks require a bit more care and longer curing times.

Post welding inspection: Its time to inspect one last time before the water test. If you notice areas that have not been welded properly (a visual inspection will immediately reveal mistakes) simply apply more solvent and hope for the best while repeating previous step. You might be able to fix the problem area by adding more weight but not always.

Water testing: Do not remove the film before adding water. Simply place the tank on a firm surface but one that allows you inspect all edges without moving the tank. Look for drips and mark problem areas. Dry the tank well with a towel and allow to air dry 24 hours (or until you’re certain all water is gone from the gaps). Look carefully and try to identify the leak. About this time you’ll wish you had just purchased cut pieces. If you must, you can remove roughly ¼” strip of the protective film from the bottom plate to aid inspection. Be warned that any film you remove will expose the tank to solvent. In most cases, you will unable to further weld the tank but applying solvent again with weight can’t hurt as long as the protective film is intact. Generally corners are the most susceptible to leaks and are also the hardest to fix if not properly fit in advance. A little dab of silicone is an excellent last resort for corners. The corners are out of the viewing area so this is not a great concern.

The tank portion is done and you can remove the film but handle carefully since acrylic can easily be scratched.

This is the way I’ve found fits my primitive technique and in no way am I suggesting this it the most efficient or best way to make these tanks. I hope this helps and I’ll add instruction for the paddle shortly and perhaps the protective case as well.

Awesome! Thanks for taking the time to "construct" this post Uland!

Todd

Woooo! I've been waiting on this.

Thank you x 1,000,000

I built two out of plexiglas a month or two ago. They work great.

My pleasure Todd and Steve. I've been meaning to do this for many months now.

I built two out of plexiglas a month or two ago. They work great.

That reminds me...plexiglas/acrylic all the same but don't try and use the #4 solvent on "Lexan". A different solvent should be used with Lexan.

Nice post Uland, I just made one out of glass a month ago.
What are the advantages of acrylic? I was scared of scratching it easily.

Paddle construction is pretty easy compared to the tank but getting the width exact is critical later when taking photos.

Materials:
1/8" thick acrylic sheet
#600 grit sandpaper (and other)
welding solvent
jigsaw
sanding block
flat spray paint

The layout and sanding will be identical to the tank design above. Simply measure the inside width and height dimension and cut the acrylic as before. Try and oversize the with by 1/32" and sand that dimension to fit so the paddle moves from front to back when held parallel to the front pane of the tank. With a tight fit, you will hardly need to hold the paddle when photographing small fish and therefore not need to actually "squeeze" them. Now that you have a snug fit on the paddle, round the corners slightly and make sure and round all edges well to prevent damage to the tank. With some of the scrap, cut a handle and two small strips to later weld the handle to the paddle. Below I've photographed the pieces and the general arrangement.

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With all of the pieces cut, corners and edges rounded you can begin roughing up the surfaces with #600 grit sandpaper in preparation for painting. Use your sanding block in a circular motion until all portions are well scuffed. I like to drill a small hole in the center of the handle to help me later hang the paddle to dry. I show below what the scuffed acrylic should look like.

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I now clean all pieces with warm soapy water and allow to dry. Center the handle and tape the pieces together as shown below.

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Apply solvent to the first side then flip the paddle over at once and make sure all voids are filled. Allow to rest for about a minute and press firmly on the strips adjoining the handle to the paddle for about a minute. Let this weld cure for at least two hours, remove tape and then sand out the imperfections left by the welding solvent. I once again clean the paddle in warm soapy water and allow to dry.

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I now use flat enamel paint in from a spray can and apply several coats of white until no light can be seen through the plate. Hold plate up to very bright light and check to be sure. Make sure and sand with #600 paper between coats of paint to assure in binds well to the previous coat. Use any color you want but it's nice to have a two colors to accommodate the different fishes and conditions.

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Once again I'm not suggesting this is the best or only way and I see plenty of different ways to make the paddles.

Nice post Uland, I just made one out of glass a month ago.
What are the advantages of acrylic? I was scared of scratching it easily.

Acrylic weighs much less than glass and isn't brittle at all. I use acrylic since they go into the field under less than ideal circumstances. I make a protective case (which I will post about later) and stuff them in back packs, drop them on rocks and I simply don't see glass holding up to field use. Oddly the glass commonly available at the hardware store is full of waves, dimples and various other imperfections. I've sourced glass certified free of defects but it ain't cheap. Acrylic really scratches easily but I've been able to keep the tanks in decent shape by using the case (which would be required with glass as well). If I were able to keep the tanks out of the field, I would also use glass.

Almost done

Once again I'm certain there are many ways to protect your photo tank and I'm not suggesting this is the best but it's a start at least.

For the protective case you'll need 3/8" plywood, glue, nails, small hinges, handle, small chest latch and weather strip.
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When designing the case, take into account the thickness of the plywood and weather strip and add a little room for the paddle as well. I construct the case in the same fashion as the tank with the addition of the top. I don't fuss much on the case since its designed for field use. I use cheap construction ply.
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Once the case is sanded, I give it a quick coat of stain and a few coats of urethane to protect it from the elements.
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Next I install the hardware as shown.
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I then cut the adhesive weather strip to fit the case and press it in. This will not only prevent the case from scratching the tank but will also provide some cushion.
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I also make a small felt or terry cloth bag to hold the paddle (prevents scratching) and often wrap the tank as well when transporting.

Good luck and please ask if you have any questions.

Awwww...Snap... That's what I wanted to see. For a year now I've been eyeballing that case. Thank you.

Thank you very much for posting this. I, unfortunately, do not have the resources to put this together. But I got word that there is a supplies area for the research lab on campus that does have these resources. Although they don't let us use the tools, they'll put things together for us. So...looks like I'll be printing this out and handing it in, and hopefully I'll have a new photo tank for the lab that will double for personal use in times of need (which will be often).

Thats a great way to make a photo tank. I used to work for a sign maker and we would glue together signs with that method. The seams if done right will be stronger than the plastic. Another option for this type of tank would to buy a pre made plastic box. You can get some at Tap Plastics http://www.tapplasti...ct.php?pid=222 They are fairly common around my area I don't know about the rest of the country.

Thanks for posting all this, Teleost! I'm going to have to build a couple of these in the near future.

Whoa, TAP plastics - that website has all KINDS of neat stuff.

Sweet...Very nice Teleost one of the better how to articles out there!!

Hey Mark! I was getting worried about you. As soon as the ice breaks we gotta get out. I'm going nuts sitting indoors

Thanks for all the kind words everyone. It's been my pleasure to put this post together and I hope it helps. When I started trying to make a photo tank, they were awful and I almost gave up. Many attempts before I could even use one for photos, I hope this cuts your learning curve in half.

I feel obligated to post the link that got me started. I honestly meant to provide the link in my fist post. http://www.duboisi.c...k/bndiytank.htm

Just had my photo tank completed going off instructions from this thread. Couldn't wait to start taking some photos. Here's the stuff I did this morning. Now, if there was an instructional about how to position the fish and about how to catch the perfect "light". The photos of the Red Shiner were when I didn't think of opening the blinds in my apartment to catch some sun rays. The Striped Shiner was from when I got a little wiser.






THANKS AGAIN, ULAND!

Edited by NateTessler13, 13 March 2008 - 09:40 AM.

Very cool Nate. That sure was a quick construction and it looks like a fantastic weld (better than any I've done).

Keep your eyes peeled in American Currents for photo tips as something might be in the works.

Just had my photo tank completed going off instructions from this thread. Couldn't wait to start taking some photos. Here's the stuff I did this morning. Now, if there was an instructional about how to position the fish and about how to catch the perfect "light". The photos of the Red Shiner were when I didn't think of opening the blinds in my apartment to catch some sun rays. The Striped Shiner was from when I got a little wiser.






THANKS AGAIN, ULAND!

Well perfect light is hard to come by. Photographing things outside is best on an overcast day. (Diffused Light) If you had a window and it is very sunny outside diffusing the light with some sort of lace material is best. Hard to beat doing photographs outside on a overcast day though. That is the best light for any sort of out door photography. Well unless you are catching sunsets or sunrays or fog. But I think you get my point.

Diffused sunlight

Daniel

I want to thank you again for posting this Uland. I busted glass tank #3 on Friday night, and I'm just gonna have to go visit my Dad's table saw after using Nate's this weekend. It's just not worth it

Todd