A question for you acrylic repair experts

[qu13tst0rm]

I picked up a used 240 that has a patch repair, a crack from corner of one access hole to the front edge.
Tank is 8’x2’x2’; pre drilled for schedule 80 bulkheads, and has built in corner overflows.
Front and Back panels are 12mm.
Top, Bottom and Side panels are 10mm.
The tank holds water, but I want to remove the patch and install full bracing around the top.
The patch pieces are 10mm x 2” wide, welded above and below crack, and on Front panel.
Is it possible to safely remove the patch piece on the top only?
OR should I just cut to fit bracing around this piece?

 

[aldiaz33]

You may do more harm than good trying to get the repair off. Usually acrylic tanks are reinforced on the inside. When you say you want full bracing around the top are you just looking to reinforce the seams? If so, I would take acrylic rod and weld it on the inside seams.

If you ever see a crack running like that, it's best to drill a hole at the end of the crack to get it to stop running and then reinforce. Probably doesn't help you now, but just in case you see it grow down the front, this is what I would do.

Good luck!

 

[qu13tst0rm]

My plan is to reinforce the top perimeter (eurobracing?), then remove one or more braces between the access holes. These holes are 17"x8.5" and I want to re-home my 22" Pacu. With the current access hole size, I would have to put the Pacu in Head first, holding him by the tail. I will post another thread on removing the bracing.

 

[aldiaz33]

If removing a brace is a necessity, I would remove one of the side braces and not the center one.

 

[wednesday13]

Bad idea IMO to hack it up any further...i've repaired alot of tanks, broken bottom,exploded backs, and ive never seen a crack run down the front panel. I agree with aldiaz33 about drilling holes to prevent further spread of the crack, even through the patch material. If the previous repairmain did a shotty job on the patch, you may be able to stick a flat screwdriver in a weak spot and hit it off with a hammer if you wanna go that route. "Eurobracing" is for glass tanks, similiar to acrylic but the more acrylic you have on your top/lid piece the better. It will bow no matter what you put on there and eurostyle (individual pieces) may pop off after the tank is filled for a period of time.

 

[wednesday13]

I believe that pacu will fit through those holes, you may get wet lol but he'll go right in on his side. If you cut the braces too much tank will def. explode eventually and the pacu wont have any home. Only way to change the top piece like you want and repair the problem is to cut the entire top 3" off around the tank below the crack, sand it level, and throw a whole new top piece on with a bigger hole if you wish. Hack job for shure but possible, overflows would be tricky. OR you go the more reasonable route of no cutting. If you get lucky and can remove/improve the patch i would stop there. No matter what you do for bracing the crack will keep running unless you drill a hole at the end of it. Previous owner could have prevented this by drilling through the top piece when the crack started (before it ran to the front panel). I have a 180 tall with a similar crack on top that was stopped in this fashion. Weld on #40 is by far the best! i would recommend it for any more patch work you do after drilling. You can get by for a while with #16 or #4 but ive had patches crack off after a few years without the #40.

 

[wednesday13]

sorry to rant lol but i also have a 300 that has the top bracing cut. The center brace is still there but they cut the holes all the way to the back wall to make room for h.o.b. filters. Complety stupid! My back wall is 3/4" most 300's are
1/2"and it bows terribly now. 2 years ago I glued on euro bracing style pieces with #16 to span over the top for some extra supports and 3 out of 4 have popped off. Essentially all the bowing in an acrylic tank is controlled by the top piece being whole. The top piece is under so much stress it bows upward, this is why cracks are common on the top like yours. May sound like alot of nonsense but i have experience and i'm just trying to help. 80% of my own tanks were acrylic repairs aswell. LMK if you have more questions

 

[qu13tst0rm]

Whew... glad I didn't rush to fill this thing. On closer examination, looks like the crack has started down the front. Will have to verify tomorrow in natural daylight (if I get some). Also looks like the drill trick was attempted on the front panel, but they missed the crack by a couple of mm's. The crack is 1/2" down the front, the patch peice is 1" (2" wide). Looks like watever was used to weld the patch peices on might be deteriorating, like air pocket forming underneath patches. What size drill should I use? Or is it too late. Can get more (better) pix tomorrow.

 

[wednesday13]

you took good pics...i noticed that crack right away lol nice documentation. Its good news the pieces were glued in poorly if you can get them off. Dont struggle to hard though to remove it, one or two hammer swings maybe hah, your prying could cause the crack to run. If the piece is indeed stuck for good, get inside the tank and drill outwards hitting the crack where it ends. If you miss its ok just try again until you can clearly see you've got the nail on the head so to speak. With a 1" thick patch on the outside you have some leeway (Only drill through the original front wall not through the patch on the outside).By doing this it ensures the tank is still waterproof as long as that patch is on good. Very easy to glue a small hole and around the edges of the old work with weld on #40. you should be able to pick up a small kit for $50 or less you dont need much. I use the smallest bits i can find on hand for drilling, anything 1/16",1/8" is good.

I guess let me know if you can get the pieces off easily first haha.... if not go for the above

 

[wednesday13]

what looks like deterioration is bad adhesion by using the wrong type of glue. There is a huge misconception about weld-on's products. I myself started out thinking weld-on #4 and #16 were the best until I read straight from their website about #40 a 2 part epoxy. It clearly states "this is the glue used in the aquarium industry to achieve crystal clear seams" right on the product description. If you watch "Tanked" you can see them mix this glue in cups and pour it along their sheets before they assemble...this is not how i learned just proof im not crazy lol. They also use it to repair a cracked tank from a bulkhead. All they did was pour it over the crack and left lol.