Rules of thumb

Tony · Post by **Tony** » Fri Sep 30, 2005 5:32 pm

Hey y'all,

I just bought a new project, now that I'm living on land again with a shop and a long driveway. I bought a Bahama 25 (supposedly, I haven't been able to find much info, other than Clackacraft built it using a mold they purchased from a private party, and it maybe could have been an ex-islander mold-Islander 26? I haven't been able to find any pics of it online) empty hull and deck. The hull was damaged in the factory in '84, so they never finished it. It's been stored indoors, so appearances wise, it's in great shape, other than the bit of damage on the hull. Hull and deck are seperated, I've got hatches, the rudder mold and the glass shells of a new rudder. Here we go.

Tim, I'm sure your site will once again become my textbook.

Here's a few questions to start with:

1. Ballast: I have an empty hull with a shoal keel that would have had lead in it, should they have finished it. A) Not being able to find any of the original specs on the boat, how do I go about figuring how much ballast I need to put in the keel? B) Do I need to go with lead? What about other materials? It's encapsulated, so I think I've got more options.

2. The Rig: How do I go about finding out what kind of sail area I'll need to drive the boat? I'd like to rig it as a cutter with a 'sprit. Do I start looking at other similar sized boats and guess? Is there some formula?

3. Anyone know of a cheap source of boat stands in the Northwest? :-)

Thanks a bunch!

Post by **Tim** » Mon Oct 03, 2005 7:03 am

Wow, tough questions. Congratulations on your new find, though!

Ballast and sail area are, of course, incontrovertably connected and related; each depends entirely upon the other, as well as other design factors. Neither is a place you want to make significant errors, nor do you want to just SWAG the amounts.

I suggest that you will need to have a boat designer involved for these basic calculations. Since you're in a position to dictate, to some extent, the results, you can allow for more sail area initially and go from there. So many factors can come into play here--draft, waterplane area, wetted surface...it boggles the non-engineering mind.

I would think that a designer would want to take offsets of the hull so that its shape can be recreated on CAD, and then go from there. However, this is not my field. Since you have no existing specs or plans, or even ideas about weights or what the relative sail area or ballast should be, I just don't see any option than to involve someone in the design field...unless, of course, you want to wing it and possibly come out terribly wrong.

I would highly recommend lead for your ballast. I'm sure you have a limited area in which to place the ballast, and, lead being the densest of the commonly-available materials, you'll be able to fit more weight into a smaller area. In addition, using lead keeps the ballast deeper and more centralized in the space, both of which are better for the overall trim and stability of the boat. Avoid all temptations to use other materials in this application.

Good luck with what should be a challenging and interesting project!

MikeD · Post by **MikeD** » Mon Oct 03, 2005 9:24 am

A few years back, a fellow on the ODay list added ballast to his boat by melting down used tire weights he got from a tire shop. Could be a good cheap source for lead...

Tony · Post by **Tony** » Mon Oct 03, 2005 5:10 pm

Thanks Tim,
I'm working on getting some more info on who the designer is, I'm told by the guy at Clackacraft he thought it was someone who had designed boats for Islander. I emailed Bob Perry, up in Seattle. He didn't recognize the boat from the meager pics I had, as soon as I get the hull home I'll take some more and give it another try. Since Clackacraft purchased the molds, my best guess is that it's an old Islander mold. I haven't found email or mailing addresses for any of the other designers who worked for Islander. I was hoping to find some pics of the different Islander designs, maybe I can recognize something. There's a couple of 26 and 27 foot models I haven't seen yet, anyone have any pics in their files?

As for the lead, yes, I thought about the tire weights. Yes, I may do that, but I'm really not sure I want to be smelting lead. We'll see. I don't have a large budget for this project (big surprise, huh? I mean, I know you're all independantly wealthy, and this is all just a big hobby, right? :-), so I'll have to see what I can do. That may or may not be the best option.

Keep the ideas coming!

Post by **Tim** » Mon Oct 03, 2005 5:49 pm

Certainly cast lead keels are not inexpensive, but you may be able to use pigs and other weights inside your ballast cavity, since you don't have an external ballast pig.

Also, since there's room for error and the casting, if made, need not be perfect, it might be an interesting time to self-cast, if you're so inclined. It takes a bit of work, surely, but if it's an exciting prospect for you, then it would be an experience.

Another possible source for lead might be derelict boats--salvage them for their keels, and cut up the ballast to fit your space.

Regardless of what you choose, here's an interesting article on casting a lead keel from scratch.

http://www.rutuonline.com/html/wheel_weights.html

You might also check out Larry Pardey's "Details of Classic Boat Construction: The Hull", which has a section on casting the lead keel, as I recall.

Figment · Post by **Figment** » Mon Oct 03, 2005 7:32 pm

Most tire places now have arrangements with the recyclers that haul away the old tires and weights. The price they charge for hauling away the rubber is affected by the amount of lead they take. Few tire places are giving away lead anymore.

Wrecked/salvaged boats are a better source nowadays. Find one that's similar enough to your desired finished product, and you'll have a stockpile of hardware and rigging to boot.

JetStream · Post by **JetStream** » Mon Oct 03, 2005 8:55 pm

I found it fairly easy to cast the lead in manageable chunks. I lined my keel cavity with 6 mil polyethylene sheet, then poured in part A - part B urethane foam to make a male pattern. Then I cut the pattern into manageable chunks with my bandsaw. Then using sand from a local foundry (it really isn't hard to get), I made open mold cavities with wooden frames, the foundry sand (wetted to allow it to be packed against the pattern) and the urethane foam patterns. After removing the patterns, I dried the cavities with a propane torch, then melted the lead in a cast iron pot on a propane fired turkey roaster. I did the chunks at about 100 pounds each for handling purposes. Then when I fitted the pieces in the keel cavity, they fit quite nicely and I epoxied them in place. You can use lead shot to fill any small imperfections with your molded pieces before you add the epoxy. You need to be careful about inhaling the molten lead fumes, and careful that you make a robust system to pour the lead without spilling it. I used bricks and levers without a problem. If you do the whole keel with lead shot instead of solid lead, it will be only about 75% as dense and thus you need more ballast as you won't have the same moment arm.

Curmudgeon · Post by **Curmudgeon** » Tue Oct 04, 2005 4:36 am

a fellow on the ODay list added ballast to his boat by melting down used tire weights he got from a tire shop.

Check with your local hospitals - they ship radioactive materials in lead containers that are used once and then disposed of. I collected about two tons that way and paid 25 cents (sometimes less) a pound. For peace-of-mind I used to have a fellow run his gieger counter over each load that I picked up. It was priceless to see the look on the neighbours' faces as I carried all those containers marked 'Radioactive' into the backyard.

Post by **Tim** » Tue Oct 04, 2005 6:57 am

The online article I quoted above also has a discussion on the author's initial choice of lead shielding material (X-Ray, I believe), but there was some issue regarding the antimony content (or lack thereof). It's worth reading before making any decisions on the subject.

This all falls into the "read everything you can first, then make your own intelligent choices based on that information" category.

catamount · Post by **catamount** » Tue Oct 04, 2005 12:31 pm

As I understand it, the antimony hardens the lead, making to more suitable for external fin keel. For an encapsulated ballast keel, the antimony content of the lead might not be an issue.

Regards,

Tim

Tony · Post by **Tony** » Tue Oct 04, 2005 1:02 pm

Thanks guys,

I've got that article in my arsenal, thanks for pointing it out though. As the "other" Tim said, the Antimony is used to harden the lead for an external keel, I don't think it's all that necessary for my purposes. Do you know of any other books that talk about this? I'm going into Portland later to look for the Pardey book. I knew Larry had written one, but couldn't remember the name of it. The derelict boat might be a good approach, I just have to find one :-) You'd think that, here in the Portland area where the majority of boating yards and marinas on the lower Columbia are, it wouldn't be hard to find something like that. I'm looking. I have plenty of space for my boat and the work, but I live downtown in Vernonia, a little town up in the mountains, so I have to make sure everything, including any salvage boats, in my yard is still "presentable" to make the neighbors happy. That would probably be the best approach, though. I'm thinking that might be the best way to get a mast, although with all the damage down south I'd think there will be plethora of salvage parts available within the next few months. Shipping might be a problem. I guess I'm rambling, so I'll sign off now :-) I know a couple of you live in the Seattle area, if you find any derelicts that look promising, please drop me an email at wilfite@yahoo.com or post here. I'm not that far away.

Thanks!

Tommy Bahama · Post by **Tommy Bahama** » Tue Oct 04, 2005 5:08 pm

Tony,

You may be able to get some of your questions answered at www.islandersailboats.com . The forum is very slow but there is a very detailed section that lists the data for each boat, including ballast and sail/mast data.

Good luck!

Tom

Tony · Post by **Tony** » Wed Oct 05, 2005 12:23 pm

Thanks Tommy, I checked it out. See below.

I went to the boat yesterday (65+ miles from home and forgot my camera AGAIN! ARGHHH!!) and took some actual measurements. The deck is ~24'2", The hull, including the reverse transom is 25'. Beam is 8'. Cockpit is 6.5' long, with a 2' top opening hatch on both sides of the seats aft. (I'm going somewhere with this)

EDIT: OK, I've tried posting this pic twice, and it didn't work, so here's a link to my site:

http://www.geocities.com/wilfite/KeelPic.html

The pic above is from a Cal 25. What I'd like to know is if any of you can think of other 25'ish boats in the late 70's-middle 80's with this kind of keel profile. My boat looks like this except the rudder is mounted on the keel, similar to a triton's, though the shape is a bit different, and the transom is a reverse transom. There isn't any propeller aperature, so if there was an inboard, the prop would most likely be aft of the rudder. My deck is completely different. Thanks for any help you can give me, Islander didn't make a 25', so I'm back to no leads.

Thanks.

Post by **Tim** » Wed Oct 05, 2005 5:49 pm

Here's the picture:

Troubleshooting note: for the Img tags to work properly, the link must have a .jpg or .gif extension. Tony, I suspect you may have been trying to use the .html link with the Img tags, which is why it would not work.

To post this picture, I right-clicked the photo for its properties, then inserted that link (with its .gif extension) here with the Img tags.

Boatwise, nothing's ringing a bell immediately. If you can get some photos of the boat, it might help.

Tony · Post by **Tony** » Wed Oct 05, 2005 8:12 pm

I'm bringing it home next monday, so I'll have some pics then.

Tony · Post by **Tony** » Fri Oct 07, 2005 8:02 pm

Hey ya'll,
On another note:

Are there any "standard" sizes for things like bunks, height off the sole of seats and so on?

Thanks a bunch!

Post by **Tim** » Sat Oct 08, 2005 7:35 am

I recommend you pick up the following two books:

Skene's Elements of Yacht Design, by Francis Kinney.

From a Bare Hull, by Ferenc Mate

Both contain useful information. Skene's in particular has a whole section dedicated to seating heights, widths, and so forth. I recommend an older version of Skene's, though I think there is some form of updated version available. You'll need to find a Kinney version through a used book seller online, but it's a classic reference text and, if you buy the older one, is full of great pictures and lines drawings of beautiful S&S-designed boats. (Francis Kinney was, at the time, a chief designer at S&S). Maybe the new version is better (somehow I doubt it), but I'm a sucker for my battle-worn old one, which I got in my teens when I was interested in yacht design. Heck, why not grab a new one and a classic one?

Mate's book is a good read, lacking in some of the detail you might need but interesting nonetheless, and probably applicable to your situation.

Tony · Post by **Tony** » Sat Oct 08, 2005 3:51 pm

Thanks Tim,
I'll check 'em out!

CharlieJ · Post by **CharlieJ** » Sat Oct 08, 2005 5:23 pm

I had "From a Bare Hull" gave it away- pretty useless book ( for me). Casey's "This Old Boat" is better and has a chapter on dimensions. So does "Yacht Joinery and Fitting" by Mike Saunders. That's another very good book. It was the ONLY place I could find a real descriptiopn of how to build a real water tight seahood and sliding hatch.

On the keel. I have poured two keels so far- Adding weight to my own keel on my previous boat also.

I had a crucible built that would hold 600 pounds of lead- had a flue pipe for a pour pipe, set on a threaded elbow. Used a rosebud type burner which cost me about 12 bucks. Melting 400 pounds of lead took 1 1/2 20 pound propane tanks. Built the mold from heavy timbers, set it alongside the crucible and did the pour by tilting the flue pipe over.

I got lead from various places. Bought 300 pounds from a tire shop at .15 per pound. Bought 150 pounds from a metal recycling place- paid .25 pound for that. Got 100 pounds from a gunsmith out of his bullet trap- that was a gift from a friend. Lead is kinda where you find it, but the tire shops and metal recyclers would be my first stops.

I do have a whole series of pictures which I posted on TSBB once upon a time but the pics are all gone from the site now. If you will email me I'll send you a series so you can see how I did it.

One VERY important warning, and I cannot stress this enough- when adding lead to the crucible and when pouring into the mold, make sure every thing is DRY- and I mean ARID dry. Otherwise you can generate steam pockets that can and will blow molten lead all over the place- 'taint fun!!!!

It should also go without saying that you'll be wearing a face plate, long pants, gloves etc and have an unencumbered escape route should something go wrong, like the crucible splitting or the mold breaking.

mishnish · Post by **mishnish** » Sat Oct 08, 2005 8:48 pm

Starting with a blank hull and coming up with a design to fit into it is quite a design challenge. There are a few ways to tackle it, but fundamentally, you are trying to balance the sail area with the ballast... can I make a suggestion or two that will get you off on the right foot?

When yacht designers start a project, there are so many variables up in the air that we must pick one or two and stick with them for a trip round the design spiral. Usually length is picked based upon the designers experience and knowledge. Then a database is developed of vessels that we feel are very similar in design and scope of operation. We include as many parameters as possible in the database, such as LOA, LWL, ballast, Ballast ratio, sail area, and many more. We can then mathematically scale and normalise these using scale factors. This will leave you with a couple of figures for an overall vessel that will be very close to what your hull needs. This is the first stage of design and can give you a much clearer picture of what the vessels design parameters are.

If you like, supply me with data on 8 or so vessels that you feel have very similar hulls to your own according to these parameters and ill see if i cant come up with a basic parameters list that will apply to your hull. Oh and dont forget to give me as much data on your own hull as you can get!

LOA (length overall)
LWL (length waterline)
B (beam)
T (draft to bottom of keel)
Tc (draft to bottom of canoe body)
Delta (displacement)
ballast weight and or ballast ratio
Sail area

With the information you can gleam out of this process you can go on to design your rig around the sail area and ballast ratio, and you know it will work because its been done before on the vesssels in the database!

And I cant recomend Larrson's Principles of Yacht Design enough! Its been my bible for 5 years here at uni!

Post by **CapnK** » Sat Oct 08, 2005 9:50 pm

Hi Tony -

How about old battery lead? I know it has antimony in it, which isn't needed in this case, but I know that there are at least a dozen batteries just sitting around on the docks here at my marina, and you usually see several every month getting carted away. Just a thought, don't know if it's feasible/desireable.

Also, Brion Toss' "The Complete Riggers Apprentice" has some really good information for calculating rig loads and etc, it may be another source for you to look at when determining what to eventually put up topside.

Congrats, and good luck! :)

Tony · Post by **Tony** » Sat Oct 08, 2005 11:29 pm

Thanks for all the suggestions, guys. I've already got This Old Boat, and placed the others on my shopping list. Thank you for the offer Chris, I will take you up on it. Expect an email inside of a week or so. Much like Charlie, my lead sources will probably be varied, unless I can find a junker boat to salvage the keel. No luck yet, but still looking.

Thanks!

Figment · Post by **Figment** » Sun Oct 09, 2005 12:23 am

Keep your ear to the ground. This is the time of year when yards are eager to get rid of old junkers to make room for paying customers.

CharlieJ · Post by **CharlieJ** » Sun Oct 09, 2005 7:22 pm

Found a link to the article and pics I posted about doing the pour of the 400 pound keel. Here's the link-

http://www.messing-about.com/forum/view ... uring+lead

mishnish · Post by **mishnish** » Mon Oct 10, 2005 8:19 am

No worries Tony!

When you pick your vessels, they dont have to be the exact length. They can be plus or minus perhaps 10 feet. The key to this selection is having the hulls as similar as possible in shape and having the vessels as closely matched in purpose and design drivers to get the right information out about your hull. When I say design drivers, I mean what the designer had in mind when he drew the hull. Was it to be a cruising family boat? Was there a tweak of performance? Does it look like it was meant to be a shoal draft vessel? etc. Having said that, you can throw a few different things into the mix depending on what characteristics you'd like. For example, if the selection is predominantly family cruiser, you could add something like a sports boat to the database to spice it up a bit in terms of performance. However, this generally applies to building a hull from scratch. What we will be doing is taking as much data as possible from designs that are as similar to your hull as possible, rationalising them, and producing a spec that will definetely work with your hull. Good luck with the selection process! And if you like, you can read one of my design projects online on my website. Its in the projects section. In our 4th year we do a design project where we all pretend to be designers and clients. My client wanted a vessel capable of cruising european canals. See what you think!

Tony · Post by **Tony** » Wed Oct 12, 2005 7:58 pm

Alright!
We got it home Monday night and Tuesday, see below for a couple of pics. Does this design look familiar to anyone?

This is the hull loaded onto the rented trailer after about 3 hrs of four guys lifting and grunting. The hull's not that heavy, really, so we had to move slow to control flexing. There are wooden beams screwed into the deck edge transversely to help the hull keep it's shape.

Here's the Deck from forward

And here's the cockpit from aft.

I'm working on a new webpage now, when it's live I'll post the URL.

Ric in Richmond · Post by **Ric in Richmond** » Wed Oct 12, 2005 8:58 pm

What a project!!!

I can't wait to watch it develop.

That must have turned some heads going down the street!!

Ric

Tony · Post by **Tony** » Thu Oct 13, 2005 3:55 am

Yea, it sure did. Gas station attendant did a double take, I met someone whoe "rebuilds boats for a living" and in general we got lots of attention. The funniest thing is that we got more attention on the way here than when we actually pulled into our little town of 2000 people.

I spent part of yesterday and today cleaning it up, it cleans up very well. some of the black stuff in the hull pic hasn't come off yet, but I'm working on it. The hull spent the last year in a blackberry patch, so there were berries that rotted right against the hull.

Post by **Tim** » Thu Oct 13, 2005 5:55 am

It's a nice looking hull. It's interesting to see the combination of reverse transom and full keel--not something seen very often. That distinct combination ought to ring a bell in terms of what the design is, but it does not, as of yet.

Post by **CapnK** » Thu Oct 13, 2005 8:03 am

Wow - "new" bare hull, bare deck - what a place to start! No recoring, no grinding off paint, no fixing DPO's "projects" or things done at the factory when the boss wasn't around - it's like staring at a new canvas, knowing you could paint whatever you wanted, starting *now*... :D

From what I can see, she has nice lines. I know she's not a Contessa 26, but for some reason (the cabin trunk?) I'm reminded of them. It'll be fun to watch this develop. WTG, Tony! :)

Tommy Bahama · Post by **Tommy Bahama** » Fri Oct 14, 2005 2:12 pm

The keel bears a striking resemblence to the early Islander/Columbia design. Since you were told that it may be a "Bahama", it may very well be an orphan of when McGlassen was contracting with Columbia to build his boats in Costa Mesa, CA...looks just like my Islander Bahama 24 from the waterline down...exept for the stern, of course.

Tom

Tony · Post by **Tony** » Tue Oct 18, 2005 6:50 pm

The Plot Thickens...
So I've found out it really is a "Bahama 25," built by Clackacraft. Cool. Someone on the TSBB pointed me out to one moored right across the dock from his Westerly. I now have a ton of pictures and hopefully I can find out who owns it and get more pics & measurements of the rig & the interior. Cool. Oh, and I just noticed this other 25 wasn't built by Clackacraft, it was built by Klickitat Mfg, Portland, OR. Who, by the way, have no internet presence at all as far as I can tell, not a single reference. Still working on a designer...

Tony · Post by **Tony** » Fri Nov 04, 2005 9:40 pm

I just got the paperback version. It's very helpful, but is not the same as the Kinney version. Straight from the book's introduction you find out that this is the original as written in 1932 by Skene himself. They say in the intro that the Kinney version is completely different, and they're a bit mystified as to why Kinney named his with Skene's title. Looks like I'll need to get the Kinney version too. :-) What a shame. :-)

Tony · Post by **Tony** » Thu Dec 01, 2005 5:14 pm

Hey y'all,
Just wanted to post an update. Another Bahama 25 owner finally contacted me when he read my letter to the editor in 48 North. Turns out my boat DOES have a link to Islander, One I didn't think of. Joe McGlasson designed the Bahama 24, which was ripped off into an Islander design and caused all sorts of problems. Eventually, Joe washed his hands of the whole thing and moved back to Newport OR, where he was from. Several years later, he designed the B25 and built them out of a yard in Newport. Eventually, he closed up shop and sold the molds to Harold Titus, who had built the plug and molds for Joe. Clackacraft purchased the molds and produced them with the addition of a "Clackacraft" sticker on each side. They eventually stopped production and still have the molds (As the guy at Clacka said..."If you're interested, we aren't using the molds and could probably works something out...")

Thanks for all the leads and ideas, I'll keep y'all updated as I get working on the boat (got to finish a few other chores first).

Plastic Classic Forum

Rules of thumb

Rules of thumb

Islander Website

Cool!

Kinney version of "Skenes" vs. the newer paperback

Mystery Solved!