datth
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In BAUE, some of us use the following tail weights to trim out our tanks. I dive on double Faber LP-85 steel tanks with Thermos DIN-only manifold and Highland double bands. These tail weights help me trim my tanks out perfectly and I can add/subtract tail weights as needed.
Parts:
1) Weight.
Tank V weight from Arrow Weights, 8 lb or 10 lb depending on your needs. I used the 8 lb block for my setup. You can get them online from eBay or Amazon. You probably don't want more than 10 lbs on the tail to trim the tanks; the rest should be ditchable. If you live in the Bay Area, Diver's Dan or Any Water Sports should have them in stock.
2) Hardware.
Everything should be 316 marine stainless steel or at least 304 stainless steel. Hardware can be sourced online through Bolt Depot (everything you need is on this page) or locally in the Bay Area at the Ace Hardware Store in Mountain View. ONLY the Ace MV and maybe Ace in Half Moon Bay are large enough, as I discovered, that they carry all the hardware you need below.
3) Tools.
Instructions:
1. Line the top part of the weight as in this picture to the bottom bolt of your tank, secure it with a nut from Part 2b above, then mark it where the tank starts rounding. You don't want the weight to extend beyond that. Don't cut or drill it yet!
2. Flip the tank over. Unscrew the weight from the tank. Flip the weight and measure it going the opposite direction. Mark it where the tank breaks again.
(Notice there's a hole that comes with the original weight.)
3. You will notice that the weight is about 1-1.5" too long, after you've made your markings at both ends. Measure twice, cut once! That is fine and you will need to trim that small part. The hardware will make up for that missing weight anyways.
Now you can cut the weight into two pieces, trim off the 1-1.5" excess, and start drilling. You can use the existing hole for the outside half (second picture in step 2 above) or drill 2 new holes like I did. Drill very slowly into soft lead, use drilling fluid, and take the bits out often.
The result when using a 8 lb weight like I did should be two modular 5 lb inner weight and 3 lb outer weight you can choose to carry. I also used sandpaper to round off the sharp corners. Hardware arrangement is as shown below.
(I melted down some lead of the redundant 2 inch spare chunk and filled in that hole, just to make things nice.)
Hope this is useful. Let me know if you have any questions. Cheers!
Parts:
1) Weight.
Tank V weight from Arrow Weights, 8 lb or 10 lb depending on your needs. I used the 8 lb block for my setup. You can get them online from eBay or Amazon. You probably don't want more than 10 lbs on the tail to trim the tanks; the rest should be ditchable. If you live in the Bay Area, Diver's Dan or Any Water Sports should have them in stock.
2) Hardware.
Everything should be 316 marine stainless steel or at least 304 stainless steel. Hardware can be sourced online through Bolt Depot (everything you need is on this page) or locally in the Bay Area at the Ace Hardware Store in Mountain View. ONLY the Ace MV and maybe Ace in Half Moon Bay are large enough, as I discovered, that they carry all the hardware you need below.
- a) 2x 3/8"-16 (thread), 3.5" (length) carriage bolts. (Same thread pitch as your tank bolts).
- b) 5x hex nuts (same thread).
- c) 5x flat washers (same diameter as bolt).
- d) 3x split lock washers (same diameter as bolt).
3) Tools.
- a) Hack saw.
- b) Drill and bits. Maybe 1-2 mm wider than the bolt's diameter. I used incrementally larger bits to enlarge the holes because lead is soft and difficult.
- c) Drilling fluid. I just used some WD-40 and some lithium grease, but I'm sure you can find better drilling fluids at Ace or Home Depot.
- d) Gloves and mask. You don't want to be breathing lead dust or lead on your hand.
Instructions:
1. Line the top part of the weight as in this picture to the bottom bolt of your tank, secure it with a nut from Part 2b above, then mark it where the tank starts rounding. You don't want the weight to extend beyond that. Don't cut or drill it yet!
2. Flip the tank over. Unscrew the weight from the tank. Flip the weight and measure it going the opposite direction. Mark it where the tank breaks again.
(Notice there's a hole that comes with the original weight.)
3. You will notice that the weight is about 1-1.5" too long, after you've made your markings at both ends. Measure twice, cut once! That is fine and you will need to trim that small part. The hardware will make up for that missing weight anyways.
Now you can cut the weight into two pieces, trim off the 1-1.5" excess, and start drilling. You can use the existing hole for the outside half (second picture in step 2 above) or drill 2 new holes like I did. Drill very slowly into soft lead, use drilling fluid, and take the bits out often.
The result when using a 8 lb weight like I did should be two modular 5 lb inner weight and 3 lb outer weight you can choose to carry. I also used sandpaper to round off the sharp corners. Hardware arrangement is as shown below.
(I melted down some lead of the redundant 2 inch spare chunk and filled in that hole, just to make things nice.)
Hope this is useful. Let me know if you have any questions. Cheers!
