Boatbuilding news, building tips, and builder feedback

An Occasional Publication for the Home Boat Builder

Glen-L Marine Designs - 9152 Rosecrans Ave. - Bellflower, CA 90706

In this issue

GLEN-L Update
  • Web site:
    • Returned email. We have had people ask why they no longer get notification of new postings of the WebLetter. After the last mailing, we got between 20 and 30 returns because the mail box was full. We had several returns because the mail box thought we were sending SPAM and rejected the email. We also receive a lot of returns because "user unknown". This means that either we or the person filling in the Guest Book entered the wrong address. If you are not receiving a notice about the WebLetters, put another entry in the Guest Book and we'll add you to the list.
    • After the last WebLetter was posted, I went back and put a notice about our newest design, the RC Model X-1. I have repeated the announcement in this WebLetter in case some of you viewed the last WebLetter before the announcement was added.
    • This issue of the WebLetter features the Glen-L 13. The next WebLetter will feature the Sissy-Do and her little sister, the IMP. If you have photos or feedback on these designs, I hope you will share them with our readers. A reminder: This section is in response to reader requests. I will try to present as wide an array of designs as possible, attempting to add additional information from what is currently on the site, which can be difficult without your input.
    • I would like to thank those who contributed to this WebLetter, particularly Nate Brown for a great pictorial of installing a jet in the Squirt.


Special notice: Resin Pumps

Some of the Resin Pumps that we have shipped may not be pumping at the proper ratio. For those who have purchased pumps, we urge you to check the ratio. If the pumps are not pumping the correct amount, they can still be used, but should be pumped into a measuring cup. Notification is being sent and we are issuing a credit to all who have purchased the suspect pumps.
We apologize for this problem. We are now in the process of looking for a new source for pumps.

Newest design... An RC Model

Glen and Allyn have been working on this for a couple of months. I put information about RC Model X-1 in the last WebLetter, several days after it was posted. So I am adding a link in this WebLetter for those who may have missed it. Building this model is a really great way to learn the stitch and glue boatbuilding process, even if you don't want to finish with RC components.

More about RC Model X-1

Featured Design: Glen-L 13

Why the Glen-L 13 came about...

Way, way back we obtained a copy of a book, long out of print, entitled DESIGN OF SMALL CENTERBOARD BOATS by E.C. Seibert. It's a strange little hard bound book, only 69 pages long, no index or table of contents; there are only two sections. Most books on boat design conveniently overlook the design of small sailboats and this was the first we'd seen on the subject; it still is.

Most of the book reinforced principals we had used. One comment did stimulate our thinking. Let's digress a moment to reiterate some basic facts. A boat has a center of buoyancy (CB) and a center of gravity (CG). When a boat is floating, these two points coincide. In designing a boat, the designer must calculate the weights, determine the waterline, and figure the underwater volume so the CB and CG are in the same position or the boat will not float at the designed waterline.

However, Mr. Seibert pointed out that this balance in the design stage is done with the boat erect, not heeled at different angles as it would be sailing. Will the CB and CG when the boat is upright coincide at each angle of heel? With most shoal draft small boats, particularly beamy ones, the relationship of upright and heeled areas cannot practically be preserved. In general, the heeled areas of the foremost sections are less than the upright area, so that the boat trims by the head when heeled. This in turn will necessitate a tendency for the boat to turn and requires correction by the helm with obvious loss of the propelling force. Could the CB's of the sections be made fairly close to a straight line, parallel to the longitudinal centerline of the boat at varying angles of heel?

We thought that designing a boat to that criteria and testing it would help to clarify the theory. Thus, the Glen-L 13 project came into being. Other criteria were required as we wanted a boat that would be frequently used. A nearby small lake with cabin and dock was available to assure the boat would be frequently used by varying people. The boat would be kept in the water, easily rigged and sailed by one person. The lake was notorious for winds that frequently changed directions, so we opted for a cat rig. The boat length needed to be under 14' due to lake regulations. With these criteria in mind, we hit the drawing board.

Even putting more hours in the design stage than any boat this size usually takes, getting the sections per the theory turned out to be a real chore. We knew it would be difficult to get close, but lines were changed, profiles altered ad infinitum. And we ended up with a section area at varying angles of heel that was as close as practical.

Building proceeded with no problems. The 1/4" plywood formed about the framework easily; the building was quick and simple. The hull was fiberglass covered and painted a bright yellow with minimal varnished mahogany trim. The complete boat weighed in a 260 lbs.

Did the theory help performance? There is no way to positively know. But the Glen-L 13 turned out to be one of the sweetest sailing machines we've tried. That opinion was shared, without exception, by not only our crew but owners of various sailboats at the lake. And in competing with other boats, the Glen-L 13 came in more ahead than behind.

The conclusion by all? This is one helluva nice little sailboat. ...glw

The Glen-L 13 has always been one of my favorite sailboats. I am not an avid sailor and I prefer the leisurely sailing of a cat rig, without the jib to fiddle with. I also like smaller boats; easier to trailer and store. ...brw

Glen-L 13 Links:
Design page
Construction Pictorial
Centerboard option
Hardware locations
Additional Photos

Designer's Notebook: About buttocks, waterlines and diagonals

This discussion primarily applies to vee bottom boats, although the terminology is similar to those with a round bilge.

The terms buttocks (butt), waterlines (wl), and diagonals (diag) are referred to on the "Lines Drawing" of a set of plans. Unless the boat is being lofted, they will have little purpose as far as building the boat is concerned. However, understanding why these lines are important, and their purpose will enable a builder to better understand how the lines of a boat are generated.

The "Lines Drawing" of a boat will basically consist of three views: Plan or top view, Profile or side view, and cross Sections taken through the hull at intervals commonly called stations, which usually coincide with the location of the frames or forms. Three primary lines dictate the shape of the typical vee bottom boat: chine, junction of the side and bottom planking; sheer, top edge of the side planking; and keel, the junction of the bottom planking along the centerline.

The keel definition is loosely defined to simplify the description. Often this line is called fairbody, the junction of the outside of the planking as it meets the keel.

If the section lines, chine to sheer and chine to keel, are straight, no other lines are required to illustrate the shape of the boat. However, most craft will have some curvature of the sides or bottom as shown in section. Most builders think of a sheet plywood boat as having straight sections; some may, but most will be of convex shape. Concavity is not practical unless it is at the extreme bow or stern, usually minimal in nature.

Buttocks are used to show the amount of deviation from a straight line the bottom sections (chine to keel) have. Buttocks are shown in plan view as straight lines parallel to the keel, usually two or three at least on each side of the boat. In section view they are straight vertical lines parallel to the centerline and spaced from the centerline identical to those drawn on the plan view. In profile they are curved lines that illustrate the height the buttock crosses the section line. These curved lines must be smooth and fair. Altering section lines and re-fairing the profile buttock line is an ongoing process. When properly faired, the lines in section and profile must be smooth flowing and fair.

However, the section line may intersect a buttock at such an angle that determining the exact point is difficult. To improve accuracy, a diagonal is used, shown as a straight line in section, usually to cross the planking as close to 90 degrees as possible. One is usually at forty five degrees to the centerline, others as required to make the definition point of a crossing line accurate. The distance is plotted from the intersection of the diagonal at the centerline, along the diagonal to the planking, at each section of the plan view. This should result in the plan view diagonal being a fair curving line. If not, the entire process is repeated, adjusting the points as required to assure each buttock and diagonal are fair lines and the bottom sections smooth flowing lines.

Waterlines are shown in profile as straight lines parallel to the base or reference line that in turn is at right angles to the station perpendiculars. Usually a minimum of two and usually more are used to define the side contour at each section. They must be smooth curving lines on the plan view and develop smooth curves on the sides as shown on the section views. The points of curved lines are shited to accomplish this; this is quite similar to what was done for the bottom.

Section lines are the frames or forms that shape the boat. If the lines are not accurate, the boat may have unsightly dips or bumps that will be an eyesore and detrimental to performance.

The finished lines are still inaccurate. On a small scale a pencil line width may represent an 1/8" or more. To finally true up the lines and get accurate sections, the boat must be lofted and this means going through the same process in full scale but, of course, the small scale drawing will make the task easier. Many years ago Glen-L decided that lofting was not that easy for most builders, nor something they really wanted to do. Imagine laying even the smallest boat in actual size, incorporating all views shown in the "Lines Drawing" for the boat.

So, when building with Glen-L plans and patterns, you can forget all of the above and not really care what a diagonal or buttock is; you go directly to building the boat!

Old guys building boats

Ray Moran has been stopping in at our office in Bellflower for years to purchase plans, bits and pieces and to talk. He has often come bearing produce that he and his wife grew on a vacant lot next to his house. On his last visit, I asked him about the boats he had built and got a lot more than I had expected. Ray is not the kind of boat builder who gets written up in WoodenBoat magazine, but he is the kind of builder who has kept Glen-L in business for over 50 years.

Ray built a small outboard hydro back in the late 30's (not a Glen-L... "they weren't around back then"). Ray didn't tell me about that boat, Mike did. Mike used to work with Ray back when Ray was a vehicle mechanic in the Torrance Fire Department. Ray talked to Mike and told him we were writing an "old guys" article about him. Later that day Mike called and volunteered to email some photos and add information about Ray's boatbuilding projects.

"When I worked with Ray, I didn't know he was interested in hot boats. I found out after he retired." Mike is now Ray's apprentice and go-fer. Mike also has the Glen-L Cracker Box that Ray made. But more about that later.

When WWII broke out Ray joined the Navy. Because he was good with his hands at a time when clever people were needed, he was quickly promoted. In 1943 he was stationed in the Pacific with CASU (can't remember what this stands for), their job was to refurbish airplanes so that they could go back into battle. At some point Ray found himself "with not too much to do", and decided to build a sailboat. Another sailor made a sail out of a parachute and a keel was made from salvaged metal plate. Though the sailmaker had never been in a sailboat, he wanted to come along with Ray to see how the sail performed. They were well away from shore, when Ray told him to get ready to come about. The sailmaker did everything wrong, the boat heeled and shipped water, a leak at bow added more water and the weight of the keel pulled it to the bottom. Ray remembered that the last part of the boat he touched was the top of the mast as it passed... sunk in shark infested waters in the middle of a war zone. Luckily they were seen by a shuttle boat and were picked up.

After leaving the navy, Ray made midget race cars and later worked as a mechanic. Fire engine technology was changing at this time and there were not enough engines to meet the demand. Ray's boss asked him if he could build a fire engine. Ray studied the specifications overnight and said that he thought he could do it. Ray built his fire truck on a standard truck body. The finished product was sold to the Scottsdale Arizona Fire Department. Ray drove it to Scottsdale to meet the Underwriter's Laboratory representative for testing. There was one test that Ray hadn't known about, the pump had to operate for two hours, with no re-fill of the fuel tank. Five minutes short of the mark, it stopped. The tester said that if he wanted to try again, there was still time, otherwise, they would have to schedule another test. Ray drove the truck to a local car dealer and they adjusted the engine to run leaner. This time the truck passed the test. At the two hour mark, Ray was told he could "shut her down", but before he could do so, the gas ran out and the motor stopped. Ray stayed to train the local firemen how to use the pump, then took the bus home.

In the early 50's Ray built the Glen-L Hot Rod and made his own water-cooled manifolds and v-drive. A friend came often to watch and said several times that he would like to buy the still unfinished boat. Ray said he wasn't really interested. One day the friend came in and started plunking down $100 bills from a roll.. finally, Ray shouted, "ok, ok, it's yours". He did get to ride in it, but it was someone else's boat.

After the experience with the fire truck, Ray took his expertise to the Torrance California Fire Department where he worked as a vehicle mechanic. Ray is a very outgoing person and he made many friends who often donated parts to his boatbuilding projects.

Ray has always built his boats on a shoestring, breaking many of the rules about acceptable materials. Old buddies from the fire department frequently drop off hardware or equipment they think he might be able to use. "Give it to Ray" is the response from friends when anyone has some treasure that they no longer want.

Ray is in remarkable shape at 82 years old. He does have problems with his blood sugar, but "15 min sanding" on his boat is all it takes to bring his blood sugar down to normal. Ray considers boatbuilding to be healthy exercise, part of what keeps him young.

Ray has built the Glen-L 14 sailboat, the Cracker Box and Mist Miss. His next project is the Glen-L Alpha 2.

Photos and Mike's Story

Squirt with Jet Power

by Nate Brown

Here is my latest project and it's finished. A Squirt. I know you must be saying "oh boy, another squirt" but look at this one. It came out great and it looks like the Missile that you put in WebLetter 53. I hope to get them side by side and get a shot of them...


Shop Talk: Books

Question: I'm going to build the Stiletto, which books would be helpful?

Answer: There are two books and possibly a video I would recommend:

Many books that have been published about boat building over the years, but most, like those by Howard Chapelle deal primarily with "traditional" boat building methods, and not the methods that most builders use today. "Boatbuilding with Plywood" speaks to the builder using easy to understand terms about the methods you will use when building any Glen-L plywood boat. The book also covers "multi-diagonal" construction (cold-molded) and stitch and glue construction. This book has been used as a text book in college level classes in the US and Canada. It has also been recommended frequently by contributors to the Boatbuilder Connection and other online bulletin boards.

For some people, one of the scariest parts of boat building is the prospect of having to fiberglass. If this is the case with you, the "How to Fiberglass..." book or video may be a good investment. Fiberglassing is really not difficult, but there is a lot of bad information out there, especially from people who work in the fiberglass industry. It is important that the right materials be used for covering plywood. In a plywood boat, the strength of the boat is in the plywood, so the materials used are not those used in fiberglass boat productions. The purpose of the glass is to protect the surface. Using the wrong materials or the wrong methods can waste a great deal of money in materials. If you are not familiar with the process, the book and/or video may save you a lot of headaches. Whether you get the book or video, or both depends on how you learn. The advantage of the video is that you get to see Allyn do it. There are things that he does when handling the glass that are not easy to communicate in writing. ...brw

Darla's corner

by Darla Schooler

The concrete used to construct the Hoover Dam, completed in 1935, could have been used to pave a road 16' wide from San Francisco to New York City.

If anyone has any clever bits or photos concerning boats, I would really appreciate any contributions. ...dgs


We often get questions about flotation. This is not something that we have a lot of personal experience with, but there is a chapter in our book "Fiberglass Boatbuilding for Amateurs" that provides some useful information. Although the chapter refers to one-off fiberglass boats, the information about flotation would also be relevant to wood construction.

If anyone has suppliers to recommend or descriptions of their experience with installing flotation, I will be happy to post them for the benefit of your fellow builders.


Recent email:

Re: New Web letter
On Mon, 1 Mar 2004

In your latest web letter in the section about cutwaters, you picture an inboard runabout. What is it? Is it one of your designs?

I enjoy perusing your web page and look forward to building my own boat soon.

Jerry Jacobs

The boat was designed by Glen Witt. The man in the photo was Lawrence Loper. There were two of these boats built; one by Glen, called "Junior" and one by Larry that he named "Jody", after his oldest daughter. This was about 1950. The boat was 13' 6" and there were never any plans available.

Subject: Shaft hole
Date: Wed, 25 Feb 2004

Drilling the dreaded shaft hole was threatening my sanity, until I came up with an easy solution. I mounted the strut to the bottom to drill through, then made an extension out of 1" cold rolled shafting. It's approx. 4' long. A friend who has access to a metal lathe bored a 3/8" hole on one end about 1" deep and turn down the other end to 1/2" diam. by an inch long. I drilled and tapped 2 - 5/16" holes on the sides of the bored hole for a Forstner bit (3/8 shank) for 2 set 5/16" Allen head set screws and ground a couple relief's in the shank of the bit to secure the bit from turning and loosing it in the bore. It took about 10 minutes to bore the hole (started against a block) and it went straight and true. I used a lot of WD-40 for lube on the shaft bearing, and it worked great and cost $5 for shafting. So there you have it - an easy way to do it and cheap!!!!!

PS. I'm building the Ski King in customers photos......Dwain Colton...Portland, Or.


Subject: Pee Wee Pictures
Date: Wed, 18 Feb 2004

Mr. Witt

As you suggested, here are pictures of one of my two failures and the final success of installing the chines on the Pee Wee. The first failure was using spruce as it came from the lumber yard, that's when I E-mailed you. The second failure was when I used hot water to bend the wood. On the third try, I used the lamination method - success.

It occurred to me that in all of the pictures and descriptions of other peoples boat building experiences, no one has ever exhibited any failures. That leads one to believe that all things must go without difficulties in working wood, just hard work is needed.

More later.
Berle Maxey

Customer Photos

Subject: Boatbuilder connection
Date: Fri, 13 Feb 2004

9:30 am Friday, Feb 13/04. Cannot get into articles on bulletin board forum. This is the error. Good luck. Thanks for all of the info and inspiration that you provide. I check this every day. Doug N

ANSWER: The problem is corrected. I was waiting for a full explanation of what the problem was from our ISP... but I haven't gotten it. The problem had nothing to do with the board, it was in our email program. There was a file that was generating a "loop" that filled all of our allotted space and would not allow the board to access the database. The ISP "isolated the file", which corrected the problem. I have no idea what the file was.

Subject: Newsletter 54
Date: Fri, 13 Feb 2004

Just a word from a new subscriber in the UK.

I have just received my first newsletter (54) from Glen-L. I have seen many newsletters over a number of years, some OK, many rubbish. Glen-L's is by far the best I have ever seen - clear - informative - and easy to read.

Thanks for some very useful information, and an entertaining morning's read. I am already looking forward to the next issue.

Today I have only one question:

Brian A (UK)

Past WebLetters can be accessed from the News Letters link in the left hand column from the Home Page.

Subject: Re: Newsletter 54
Date: Mon, 16 Feb 2004


Thanks for your response to my email, as in my previous dealing with Glen-L, you have proven to be 'fast and efficient', and of course you may use my email in your next newsletter.

I thought I might add a little about myself here:

I am fast approaching retirement and, after years of thinking about building my own boat, I decided to get everything set up for the end of the summer 2004 (I retire in October). Making for a good winter project and being ready for spring 2005.

As this would be my first foray into building a craft totally from scratch I decided on a small boat and, after looking on UK sites and finding nothing suitable, selected and purchased the plans/patterns to your 'Squirt'. (When I say this is my first foray into boat building I have in recent years helped two of my colleagues restore their 'classic boats' from the 1950/60s era). But this would still be my first from scratch.

However my grandson aged 10 years has a desire for sail and talked me into building him a small sailing dinghy, hence my second order for your 'Eightball' plans. I figured that this would be an easier project and we could get it into the water this summer working evenings and weekends. Anyway that's the plan!! I also thought I would get some added experience which would help with my own project.

In the meantime, I enjoy your web site - your newsletters - and your very quick and efficient service. I recently ordered a set of plans for a 42" model steam launch 5 days prior to ordering my 'Squirt' plans from you. I received my 'Squirt' plans 8 days before the plans arrived from the UK company. Can't praise you enough!

Once we start on the 'Eightball' I will keep you posted.

Brian A. (UK)

We normally ship the same day we receive the order... that is our part, the rest is up to the post office.

Subject: re: metric sizes
Date: Fri, 13 Feb 2004

Good morning Glen-L people,

Thanks for your web-letter. It is always nice to read and to learn from you and other builders. I am building at this moment the Monte Carlo and I enjoy it very much. Before this I build the Penobscot 17.

My advice to builders in countries with the Metric standard: buy a digital Stanley ruler and work in inches instead of changing the inch sizes into mm.
(Stanley 77-008 IntelliTape Digital Tape Rule)

Best regards.
Hans Aka

Build more boats
GLEN-L boats, of course

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