Mailbox/Blower Construction Schematics

rgecy · Sep 11, 2006

I have drafted some plans for an 18" diameter blower. The plans are for the elbow construction only but can be adapted for different mounting options. I plan to have it mounted to my Yamaha 225 Outboard. It is based on the picture below provided by Salvor6 that he uses on his 175 Outboards.

Check it out and see what you think. If someone needs a custom size, I can easily adapt the plans to suit. Email me and I can provide scale drawings of any diameter blower. I can also adjust the inlet and outlet length. The one pictured below has a 1' extension. I do ask that anyone who wants a custom design be an active Charter Member. I think its the least we can do to support this great site Marc has provided.

I have uploaded larger images to my Image Gallery that consist of a set of 3 sheets for better viewing.

View the plans here: Blower/Mailbox Plans in My Gallery

Robert in SC

stevemc · Sep 11, 2006

I was thinking of doing that for outboards too. My boat has dual outboards on a swim platform/bracket. Anyone know how I could have the blower attached? I see bigger inboard boats that have a channel on the transom, and the blower is attached at the top with another piece of channel, by a bolt. This swings down and a bolt is stuck in the channel making the blower immovable and in place over the prop. My props are 17" so I would need a 20" or so blower. Anyone got any ideas? The bracket is not very large where the motors mount, maybe 12 inches or so tall and 60" or so wide. The platform is wider and the transom is maybe 30 inches forward of the engines. I wasnt thinking of a swing down type, but one that slides brackets forward into a mounted bracket and bolts are put in. I would need to lock the steering into place while the blower is in. Steve.

Darren in NC · Sep 11, 2006

Great job, Robert! We'll see how it works pretty soon, I hope.

Steve, look down at "Hand Held Blower" thread and see reply #65 and the rest. Your question may be answered there. Hope this helps.

Best to you,
Darren

SEAHUNTER · Sep 13, 2006

ROBERT
I WAS CHECKING OUT YOUR SCHEMATIC AND NOTICED THAT IT LOOKS LIKE IT IS A NINETY DEGREE ELBOW. IF YOU DO THAT AND YOU BLOW A LOT YOU WILL HAVE TWO PROBLEMS. FIRST YOU WILL CREATE A SANDBAR ALL THE WAY AROUND YOUR BOAT THAT YOU WILL NOT BE ABLE TO DRIVE OUT OF AND SECONDLY YOU WILL BE BLOWING STRAIGHT INTO YOUR OWN HOLE AND IT WILL LIMIT THE DEPTH. IF YOU TILT IT BACK A LITTLE BIT IT WILL FLUSH OUT THE HOLE AND LET YOU DIG A LITTLE DEEPER.
SEAHUNTER

rgecy · Sep 13, 2006

Seahunter and Cornelius,

I have heard this debate before somewhere! I can see both points of view, but have questions about each.

Even when you blow directly downward the water will still push outward when it hits the bottom. So even then items will be pushed aside and possibly covered up. Thats why its important to know how deep your items are buried and when to throttle back. There was a discussion before on blowing to the bedrock. If your items are only 5ft deep and you blow 10ft deep to the bedrock, you will definately cover up some stuff. But it does seem more efficient this way (from a theoretical standpoint). I can see the predicament if you are blowing in 8ft of water and digging a 10' deep hole. The sand will pile up around you and possibly sand you in.

As for blowing at an angle, how much of an angle? It wouldn't take much, maybe 5-10 degrees from vertical. It does seem that you would have a tendency to move things around more and cover items up, but would it be that much more than when blowing vertically? It would ad the benefit of not sanding in.

You know guys, I am learning. I used what had been provided to me in books and Chagy's picture and came up with a design. Most of the blowers I have seen blow straight down, but I am always willing to keep an open mind. If I did want to tilt the blower 5-10 degrees I could always trim the motor up a little.

I am still interested to hear other input as well. We have a lot of very experienced members here. Any thoughts?

Thanks,

Robert in SC

SEAHUNTER · Sep 13, 2006

When you blow holes things definitely come out. But when you blow straight down into your own hole if you don't hit bedrock you eventually liquefy the last couple of feet of sand and make a quicksand that you can not dive in, however the treasure can sink into it where it is not retrievable. There is a limit to how deep you can dig. If you can get deeper than others you can get what they forced deeper or could not find. It would seem like the trim and tilt would be very helpful in this. If I had trim and tilt on mine I think I would use it constantly. The more I think about it the more I think that outboards may be better suited to this work than inboards. I would love to try out one of you guys outboards on my site.
Seahunter

ScubaFinder · Sep 13, 2006

Okay, more newbie input

I thought after 400 years of tides and hurricanes 90% of the treasure had made it all the way to the bedrock? If that is the case, then even if you blow something up out of the hole, it should be close to the top of the ridge surrounding the hole, no? My Pulse 8X says it will look through several feet of sand, so it seems as though you could get to everything either way, what am I missing? (other than the experience you guys have)

Also, is there truly "bedrock" at the bottom, or is it just the harder mud layer you are referring too? (will I EVER run out of questions?)

Jason

stevemc · Sep 14, 2006

Some areas there is no rock bottom, or it is way down. Yes the heavy stuff will sink all the way to rock or clay, but sometimes it will hit an area that is too dense to go any farther. Usually they just run the props slow enough that the type of sand will lift off, and float away, and leave coins and stuff laying on the bottom or rock or hard layer. In the Keys, Belize, Yucatan and Bahamas etc, the sand is very light and sometimes very deep, it called oolitic aragonite , sometimes halimeda aragonite-bigger but very light, mainly just calcium carbonate, it usually can be blown away at an idle. But some areas have quartz sand- West coast of Florida, and it is denser and heavier and might need more thrust to move. The East coast of florida is kind of a mix of calcium sand and quartz so it needs to be blown a little harder to lift off than the Keys. If there is no rock or clay, you almost have to be in the hole and checking constantly. A pulse induction MD will go several feet through sand in salt water, especially when something has been there for years. But that depends on the size and makeup of the object, usually. A small coin or ring it wont go that deep. Diesel boats usually have much, much more thrust than outboards, bigger props, carry more weight, and get much better fuel mileage, that is the main reason they are used more than outboards. But outboard boats are fast, get in shallower water, lighter, so they each have their good and bad points.

ScubaFinder · Sep 14, 2006

Thank you Steve (and Cornelius). As a serious marine aquarist I have several of the sand types you mentioned from sugar fine aragonite to crushed coral (calcium carbonate). It's funny how little correlation I make between my tiny ocean in my living room and the slightly larger one I'm preparing to explore.

As with most of my questions, the answer is...it depends on several other variables. All of the info is finally starting to sink in and make a little sense to me. When I get out to Florida, I'm going to have to take a BUNCH of people for dinner and a few beers to repay a small portion of my education...it's still cheaper than college

Thanks again,

Jason

ScubaFinder · Sep 14, 2006

Done Cornelius, and yeah, you're definitely on the guest list

Jason

stevemc · Sep 14, 2006

Jason, I also am a serious marine aquariast, I have a 125 reef tank with mainly corals and zoanthids, and several marine fish only tanks. I used to frag hard and soft corals and had a big fish room with many tanks, plus several big tanks in the living room. Sold that house, and dont sell corals, just enjoy them now. I also used to be a tropical marine fish collector. Here and in Hawaii. Do you visit Reefcentral.com? I am on there too-same screen name. When you get to Florida, stop by, I am in Sarasota-on the West coast. I spearfish too and have a dedicated freezer just for fish and lobster, so stop by for dinner. I am kind of at the point in my life like you, I am ready to buy a bigger boat, live on it and dive, fish, spearfish, lobster, invent new frozen drink recipes and new fish recipes. I have worked for the fire dept here and have a large pension, and want to enjoy the rest of my life. Steve.

ScubaFinder · Sep 14, 2006

That's cool Steve, I took my coral propagation tank down and now am breeding seahorses, that is a real hoot! I don't get by RC that much anymore, i'm jnowell, mostly in the breeding forum. I'm down to a 150g reef, a 58g seahorse tank, about 20 ten gallon fry tanks, and a 125g sitting on the back porch.

They will probably all get sold before I move to Florida though. If you missed it in the other thread, here is video of my H. Kuda seahorse having about 200 babies http://www.wfrs.org/sh/kuda_pop.wmv

Jason

rgecy · Sep 14, 2006

OK Now! Lets get back on track! This discussion is about Mailboxes not Coral Formations! A little focus please! Talk about ADD!

.............

Just Kidding! I hope the plans are addequate. I can certainly make modifications, but for an outboard I think they are going to work.

I still would like input from you guys. My prop diameter is 16" and I have made the blower 18". Is this enough room. I do not plan on mounting it over the prop but a few inches away.

What do you think?

Robert in SC

wreckdiver1715 · Sep 14, 2006

1 Inch either side of the prop is just right, and as close to the inside of the can as possible. Please build a cage forward of the prop to protect hookah lines, anchor lines, and divers from getting fouled in the prop during blower operations. One of Mel Fishers investors children was killed this way, so a safety cage is very important. Think Safety!

Tom V

mad4wrecks · Sep 14, 2006

That was a really tragic accident. The diver was 12 year old Niko Littlehales, son of award winning National Geographic photograher Bates Littlehales. All the salvage boats adopted some type of cage system around their props after that.

If you have never worked under a pair of 32" spinning props and dual mailboxes, it is quite an experience! When I first started diving off the Virgalona, I would always surface about 20 feet behind the boat, while the experienced guys would come up right alongside the boat and dive ladder.

Tom