Divinycell floats

[AlexF]

I decided to get a pair of divinycell floats for my bluewater hunting and here's what I got and the process of building it, up to the fiberglass, in which I declare myself incompetent. I tried though, but didn't do a very good job and prefered to send them to someone that knew what he was doing.

First I purchased a whole board of H80 divinycell, cut it with a blade knife and glued it with Gorilla glue. Once the two boards were glued, I passed through the band saw to make them curved at the top and hand sanded to get a nice shape and texture. Be carefull with the bandsaw as some pieces of divinycell get logged into the glade guards and catches fire with the friction.

A jigsaw will also do the job without the fire hazard.

I made 3 holes to each board, two would go from side to side to attach a flat webb rope and the third was to insert a pole flag.

For the first two I cut two pieces of pvc, and glued them to the board with epoxy glue. The other I used a piece of plastic tubbing and also glued it with epoxy, It almost went through side to side. I added some more glue to the bottom to seal the water out.

Once the glue was hard I prepared some resin (it can be applied directly to the board and will not eat the foam) and tried applying the first fiberglass cloth. My problem here was that I tried to attach the whole board with one piece of cloth and I got bumps all over.

I didn't use gloves and the resin in my hands was so sticky, much more than the one on the board, that I couldn't make the Fglass stick to it.

If I was to do it again, I would cut small pieces of Fglass cloth and apply them one side at a time. One those dry up, two more coats of resin were to be applied.

I went the easy way and hired a local that makes fiberglass auto parts and he finished the job for me, he also added the dye for the resin to turn orange.

The large one is 76 cm (30in) long and the short one is 55cm (22"). Both are 7.6 cm thick (3") and I can't remember how wide they are, but should be around 50cm or 20".

This is what I ended up with:

 

[milhouse]

Nice work!

How much $ for the div.cell?

 

[AlexF]

The H80 was about $100 for the board that made both floats, and I paid a little under $200 for having the fiberglass and resin put on the boards.

 

[seaman]

Hola hermano, have you guys have tried, the commercial Tuna floats (egg shaped) it seems that they dont crush at deep, and are fairly well priced, what do you think about that?

 

[Mark Laboccetta]

dyvinicell

Interesting thread Alex...my topic of interest lately.

I saw this post yesterday and was too busy to reply to it so I searched and searched without any luck and realized why. dyvinicell was spelled wrong. Or, maybe I'm spelling it wrong. Either way I found it and it doesn't surprise me that you've built some.

A few things I found out in my own testing. An 11Liter inflatable float has roughly 15-17lbs of lift at the surface, and looses a few pounds every 15ft. By comparison a 15L float has 27-28lbs and roughly 25lbs at 15ft.

While it seems you are loosing a lot of buoyancy quickly with inflatable floats, let's just say a rough estimate of 5lbs for every atm or 33feet so so, if you think about it they work well enough for most because the large majority of fish won't drag the spear-float line or bungee and float to 200' which is the depth a fish needs to get to bring the float down to 100' where it will have very little effect on a fish and can actually cause your gear to sink. In addition, the increased buoyancy/drag of an inflatable float near the surface discourages initial plunges to those depths, which can be good or bad because too much resistance and a crappy shot and it will rip out. None the less, there are other factors to consider such as ease of travel and transportation and weight with inflatable floats which makes them more appealing to most divers I know.

Well after testing one of our new Shardana Float boards to 300' a few months ago, and seeing that it literally provided no buoyancy past 150' for practical purposes (5lbs), and only 10lbs to 150', it struck me what the pressure on hollow objects is at those depths. This Shardana board of ours is molded by rotational molding up to 4mm thick in places and you could stand on it without denting it. It is hollow and provides roughly 48lbs of lift at the surface. I could only imagine, seeing this implode the way it did at 300ft, how worthless inflatable floats are past 100' for large tuna or gamefish that dive deep. I rationalized it by reminding myself that I've never even shot a fish even close to capable of doing that and that I also always dive in less than 200' normally where the inflatable floats would be more practical.

However after a little research on Dyvinicell and talking to a few experts, I thought about how I'd like to adapt my Shardana to the rigors of serious blue water hunting without going through all the trouble of making it myself. I settled on an 8lb density two part polyurethane foam, drilled a hole in the top of the Shardana and poured it, it took me about 6-7 pours over two days to get it right as the expansion rate is fairly unpredictable but I was happy with the finished product. Conclusion, the board now provides 38lbs of buoyancy at any depth and the only sacrifice is that it now weighs 18lbs as opposed to 10lbs originally. I'll send some pictures of the process that I took. The process was a pain and I'm glad to say I won't be doing it again but it was obviously less work than what you probably had to go through.

Here's one of the only Dyvinicell commercially available boards I know of.
http://www.redseaoceanadventures.com/new_page_12.htm
Also keep in mind that claims of 80lbs of lift or similar amounts in inflatable floats are most likely bogus. The Omer Shardana is a bi board and it only had 48lbs at the surface. Lastly, crab pot floats like we have here which I imagine are like the commercially available tuna floats I assume you speak of, use a softer low density foam that easily compresses at depth, not much better at all than inflatable floats.

Clear waters,

Mark

 

[Mark Laboccetta]

Alex,

Here are some pictures of my project.

How much did yours weigh out of curiosity when it was done?

I will most likely use this board for blue water hunting for big tunas or the rare exotic trip and a bungee. For the rest I like to use an 11Liter and 15Liter rigged in tandem with a regular vynil float line.

Mark

 

[Spinal Tap]

Daryl Wong and Rick Bettua made some dyvinicell floats for some customers and they surfaced those floats with Rhino Lining. I'm not sure the grade of dyvinicell cell they used, but they floats were pricey.

 

[Huan]

I have looked into the Divinycell too, I think that the stuff that is really expensive is the HCP stuff.
I think it stands for High Crush Point or something like that.
But I need a treetrunk first before I need a Tuna float.
Nice articles BTW both AlexF and MarkL

 

[Daryl Wong]

Aloha Spearos,

Interesting thread on floats. Its funny that my partner Rick Bettua and I have been doing blue water long enough to see that there is a reinventing of the wheel in blue water diving. Particularly floats. Terry Maas sums things up great in his blue water hunter book. And in it you can see the evolution of multiple lifeguard floats and single divinylcell floats. We both started out with the multiple floats and then changed over to the single float system. One of the main reasons was a safety factor. The more floats involved the great the chance of entanglement while bringing up a big fish. We have seen the power of even small tunas dragging down three hard floats over a hundred ft down before returning to the surface. This could be fatal if you should get caught in the float line. Also there is constant drag with only one float vs three floats wildly spinning down in the water column.
We have made many floats and now because of travel restrictions on weight have been doing R & D with multiple floats again. But his time with a large well built inflatable and a hard float. This combination lets you travel with less weight and still have something to land large fish. The benchmark of floats is still the one divinylcell float system. There are many different grades of divinylcell and I will let my partner Rick respond to that. He is our techie and I am the grunt who shapes and sands.
Optimum floatation should be around 50-60 lbs and larer if targeting bluefin tuna. Remember you want a float that can hold up at least ten percent of the dead eight of the fish. 1000lb tuna then 100 lb floatation.
Here are a few pictures of the different float combinations.

Aloha, Daryl

 

[Aimrite]

Aloha everyone

I have been making board floats for tuna for well over 10 years and in doing so I have bought more than my fair share of Divinycell over the years so let me see if I can help.

We started off with Lifeguard Floats filled with the Highest density liquid foam available 4 lb (btw 4lb liquid part A and 4lb liquid part B does not equal 8 lb density, it is just 4 lb!). Many folks have used this same product in building boats, usually 2 lb liquid foam is used to provide bouyancy while the heavier 4 lb foam is a requirement from the USCG to be poured around fuel tanks. Needless to say we found out in short order that this type foam was a bust! It does crush and very easily I might add.

In about 96' we shifted to board floats and used 6-8 lb divinycell with a heavy layer of fiberglass over the top. One interesting note on size is to shoot for about 60 lbs of bouyancy but that is a totally different topic. The problem with the fiberglassed floats was wieght and the fact that they would get damaged during flying to our destinations. So over the last couple of years we shifted to H-200 (12lb)and H-250 (15lb) the material is so tough you could drive a tank over it so there is no need to fiberglass we just simply shoot it with Yellow Rhino Lining so it will prevent puntures and to be easier to grab in the water.

Now for all you nay-sayers that say why is it so expensive I pulled an invoice and here is what a sheet will cost you;

H200- $742
H250- $848

Rhino lining is actually cheaper than fiberglass and is about $80 per board. Then you have to laminate the 2" sheets together so you will need some West System Epoxy. Lasty figure at least 2-3 hours of labor! :naughty

I hope this information helps

 

[Amphibious]

This is why I love this board

A "simple" float thread, that is still on it's first page, and already we have Aimrite, Wong, and Omer represented

 

[Aimrite]

Aloha

Here is what our latest generation looks like. If you cannot see it it has a carbon fiber tube laminated and running the center length. Approximate size is 16" X 32" X 4"

Rick Bettua
Aimrite Inc

 

[miles]

Hiya

We use a close cell type of foam for our body/boogie boards. The first models were normal body boards which you can purchase at any sports store. These proved to be hopelessly inadequate!! TWO body boards, lashed one on top of the other was then tried.......also unsucessfully. After these failed experiments, and stories of tuna swimming away with spear, bungee and body board, the closed cell foam boards were made. The final product ended up measuring 105cmx55cmx9xm. The smaller ones have been pulled down to 40m with-out any signs of damage. Quite a few YF in the 80-90kg+class have been taken with the current body boards, and none has been able to pull the board deeper than 10m. Most of the large YF i've taken didn't even manage to pull the board under.

Now for the best part!! The board plus bungee completely rigged can be made for less than 120Us$!!! The closed cell foam is cheap enough to buy large quantities of and experiment with it. Possibly look at making a collapsable one for travelling, as decribed by Terry Maas, in Blue Water Hunting.

Regards
miles

 

[Mark Laboccetta]

What I did was take a stock float and decided to improve it and modify it to suit my needs. I figured others would be interested in seeing how easy it was considering these boards are less than $200 and designed for 95% of spearfishing applications. This Omer Shardana float was not designed to be dragged down hundreds of feet just like life-guard cans weren’t either when Terry Maas used them to shoot his world record bluefin. My friend Rene Rojas told me Terry (bw papa smurf) was using 8lb density foam in his life guard cans so I decided to use the same. Dyvinicell is not offered in a pour foam so I used what was. It was a half day job although it took me longer since it was during a work week. I don’t have any immediate plans to shoot any 1000lb bluefins and figured the extra $50 modification and time was worth the trouble on the stock float and it would be good enough for any fish I might get to shoot. The downside is these things are big and heavy (18lbs) and a pain to transport. I'll probably just end up keeping mine on the boat. Amazingly they pull on the surface as easy as an inflatable float and don't "dig" because of the shape of the keels and the balast compartment in the front.

 

[Mark Laboccetta]

By coincidence since the Wong/Aimrite crew is reading this and to keep things in perspective I should mention that the biggest wahoo I ever shot, 87lbs, was using one of Rick’s Aimrite yellow floats 5 years ago and I figure that float probably had somewhere between 11L-15L of air so go figure, you really only need a monster float to do the job on a monster fish. Although I did get a bit worried when it didn’t come back for 15 minutes… A friend of mine on the same trip shot one that went 105lbs also using an inflatable float made by the West Coast competition and he didn’t see it for a good 5 minutes but it did come back. We’ve since began to make our own specifically designed for “dunking” and its quite interesting to see their effectiveness for most practical purposes. I’m also for the 1 float do all approach because if there’s on thing that drives me crazy it’s tangles and the inconvenience associated with multiple floats when you’re trying to concentrate on the fishing.

Mark
ps- the SS welded eye bolt is 9mm thick and through hulled with 2 bi SS bolts. It can be removed and the front flag hole can be used instead. board is 36x5x17.5"
pps- Rick - no green water for me, the sharks are big there and you can't see them I'm married now and my wife won't like it.
pps- congratulations Sailor!

 

[AlexF]

I'm proud to write that it took me a long time to repply to the thread because I was testing my floats in the water.

Unfortunately, the large tuna didn't cooperate and I was not able to see how these floats worked over a large fish. I had one opportunity at a large tuna, but it was the first day and I was using a new extra large gun, so my aim was not right and I missed the shot, actually I missed 3 shots at tuna.

Regarding some points made above: the boards are cumbersome to carry around when traveling, specially if traveling by air, but I keep the floats on the boat, so I don't have those problems. If I was going to travel, I wouldn't even think about taking the divinycell floats, I would use the inflatable ones.

Regarding the Divinycell, do not even consider the HCP. That one is made in Europe and must be special ordered into the US. I was told it was EXPENSIVE and I don't think we need such a tech foam. I spoke with DIAB's research lab to find out what was that I needed and after explaning what I was going to do, I was told that I could submerge a H60 foam to 200ft and it would only deform it's original shape by 5%. I decided to go a grade stronger to H80.

Divinycell foam is expensive, so it's worth applying at least one fiberglass coat to avoid dents or deterioration. If you are ready to screw up a few times, then applying the FB shouldn't be too difficult or expensive. H80 is stiff enough to use it as it comes out of the box though.

The only thing I would worry about when using these floats covered with fiberglass is that if I catch a large tuna, and the board hits you in the head as it passes through, it will knock you out for sure, no need to worry about swb, the board will do the trick.

One last thing, I used flat webbing to attach the shark clip to the end of the board, if the pull is not exactly in the center, the board doesn't sink straight and it creates a lot of drag. As I said before, I didn't catch anything large with my floats, so can't say what will happen when the board is pulled underwater, but when pulling from the rib boat, the float would sometimes dip the tip into the water and it was impossible to pull.

Another nice thing about the floats was pulling the fish up. I would lie over the board and pull the fish right up. The board floats so much that pulling the fish was easy.

 

[Daryl Wong]

Hi All,

One thing you should remember about using a float or any float while fighting a fish. If you should happend to bring up a fish that may qualify for a world record, you have already eliminated yourself from consideration due to using the float as a rest. May as well jump on the boat and pull it up.
Check the rules, you never know.

Aloha, Daryl

 

[icarus pacific]

Good stuff everyone!

Up or over here, floats are more for use in getting out to where you're going to dive and once there, for hanging your stuff off of. The best floats are sadly no longer made due to supposed expense, but then what's new about that? :head

The evolution has gone from simple inner tubes and burlap bags to all manner of inflatable mattresses to boogie boards and now back to inner tubes, albeit with a nylon cover over it with attachment points and pockets. Bottom line is that while great for storage once out there, they're as easy to get through the water as pushing chain. :crutch

I've been doing some design work for an all in one float for a couple of years now, and just as with spearguns, there's not one perfect gun, although Daryl's hybrids are pretty close. I went the inflatable tube, a Riffe, then did the lifeguard can, daisy-ed them together and all but the amount of drag combined with a 110' floater/bungie made me want to leave it on the boat and just hope the reel didn't jam.:martial

Being real familiar with laminates and composites, I knew real quick that going the Divinycel route was going to not be cheap and for the few times a year I actually need a float that big, I went the ready-made route. I've taken my Omer float (thanks, Mark!), a Shardana and filled it with 12 lb foam and mounted another D-ring on/under the rear for daisy chaining. While the board tows real, real nice and there's all knids of places to clip off your stuff, it's still not capable of holding my chest and head out of the water and over the kelp. But then, there are no YF or BF here so it get's left in the spare bedroom/gear shrine, and the inner tube gets brought out.

That Shardana float has the best of everything going for it, and though I don't know the specs on it's bouyancy it tows real well , takes a beating and cleans up nice, rather like me. :king

PS Daryl, answer your phone.

 

[wdaf]

i am living in the philippines, and cannot find sprayable open cell polyurethane foam for filling my floats.

any recommodations which type of foam and where to order online?

thx,

Wolfgang

 

[Witch]

I know this is an old thread but can we re visit it ........

Any one have any new designs that works better for them than these that were made in 06?????