Hull fiberglassing question

[Pipefitter]

Yes I have,which is how I knew how to arrange the wood from building decks. Mine were only 1x2 DF. I chose the highest ring count I could get and it was clear vertical grained. A little lighter colored than I like but thats all I could get locally. I fastened it with both bronze screws and bronze ring shanks in between.The old boatbuilder I used to help told me to use both screws and ring nails. One helps the other or something. Same as with the bottom planking with predrilled holes into honduras mahogany frames.The keel has 3 layers of 9oz. glass. I am hoping for the best. I can't see standing a typical 1x on edge with any width to it though.That would seem problematic. Thanks for the explanatin to clarify that. I noticed in wooden boat mag,Where Ellis Rowe while building the Simmons sea skiff that the shoe (keel?) is independant of the bottom. If I recall correctly,he glassed the bottom first and then installed the shoe after. I hadn't considered it as mine was past that point by the time I read that.

[Frank Hagan]

There have been several reports of glassed keels creating one kind of problem or another on Weekenders. Some people have had the wood shrink slightly, so that when they crank down on the straps on the trailer the glass along the edges of the keel cracks. Others have reported rot as Barry said.

Solid wood, especially the flat or flitch sawn wood most of used, moves a lot. That's why on solid wood table tops you don't glue and screw them to the apron or legs. There are usually just holding screws and a oval hole to allow the wood to move with changes in humidity. A keel on a day sailer experiences some pretty big and rapid swings in "humidity"!

I'm sure there are plenty of Weekenders out there with glassed keels that are OK, so its not the end of the world if you glassed the keel. Just look for trouble, and fix it early when you see it.

[Howard]

I've not been around the boats you folks are talking about, but in Parker's Cold Moulded book, he builds his keels from stack laminations. In this case, it would be a bunch of 2 x 4's or cut down 2 x 6's layed flat and laminated together. Less cupping or warping than larger 2x10 or 2x12's, as you could get those widths from quarter sawn wood. He wasn't all that picky about what went into the middle of the stack. Big knots were cut out and butt joints were used.

This:

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vs. this...

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The stack is glued (epoxy) and nailed together, faired and covered with Xynole Polyester....at least two or more layers on the bottom of the keel. He is putting these on 40 to 50 foot boats. Apparently they hold up.

[Pipefitter]

Howard,this may be true and he may have success but what kind of wood is he using? There is some real garbage wood out there and I think This was part of the issue. Cheap lumber from the big box store. I have had to screw some of these kind of woods used flatly with the screws on the extreme outside edge angled steeply towards the under center. The screws would stay put but after awhile,the screwheads would actually start pulling through the face of the boards as they cupped.If it had been a harder wood,the screw heads would have held better.I can't imagine using any of the cheap stuff on edge,edge fastened,with or without glassing the keel.

While I don't know about the laminated keel on the weekender,In a situation where a keel needed to be glassed,would stacked, good quality,more dimensionally stable marine plywood be better for such?

Also,it should be noted that in the case of polyester layups,sometimes there is so much heavy fabric used, that is some cases,the wood can rot and the layup of the cloths are substantial enough to hold strength and shape. I have noted this in some modern FRP boats where they had glassed a piece of lumber for stringers and after the wood was completely rotted,the stiff glass shape still acted as a stringer without the wood. The wood in these cases had become a sacrificial form for the glass,even though I am sure it wasn't intentional.

[umop_apisdn]

Could someone please explain these various methods of sawing lumber? I am not familiar with the terms quarter sawn, riff sawn, plain sawn, etc.

Does it have to do with what part of the log the board comes from?

Thanks,

Noel

[Howard]

As I recall, he only uses Doug Fir or Southern Yellow Pine. Inch and half stock. Although he is building better quality boats, at one time he did use ACX construction plywood. He may not be now. I'd be afraid of stack laminating a plywood keel, due to all that exposed endgrain. When he gets to highly curved sections, he mills the thicker stuff down to thicknesses that will take the bend, but it's still solid stock....not ply.

Polyester layups? The only use I know of for polyester resins is in layup of a totallly plastic boat. Polyester doesn't bond all that well to wood and when, not if, it gets moisture....the two separate.

If it's a real boat, intended to float, I'd use epoxy. Or put another way, if it wasn't epoxy....if it was me.....I wouldn't do it at all.

Some of you guys have built some really nice looking boats. I guess the concept is to do it as inexpensively as you can.....but if you want it to last more than a season or two....I guess I'd go the extra step. The amount of labor involved is a serious part of the equation. Shame to waste it on inferior materials.

[Howard]

ooops....just read again what I wrote. Before anyone rings my bell, I want to make it plain I was not intending any digs toward Mr. Pipefitter for using inferior stuff. Not at all.

It was intended to be a comment in general for anyone contemplating building anything like a boat from some of the really cheap utility or lower grade of wood that you buy in the box stores.

Not only is it of poor structural quality, it's relatively expensive. The market they target is some do it yourselfer, who needs a few pieces of some kinda wood. These customers neither know or care what they are buying. The wood is there and it's convenient.

Few if any commercial contractors I know of buy anything from the box stores. I can't imagine that a serious boat builder would either.

Myself.....I have access to Home Depot and Lowes. I have to drive by two large commercial yards to get to them. Rather than pay $5 or more for an 8' long 2 x 6 SPF stud at HD, I chose instead to go to the local yard. They busted open a full bundle of 10' long 2x12's, and left me to it to select what I wanted. Those cost $16 each. And the selection of different woods, grades and types is probably 10X what the box stores have. To me, its worth the effort to seek them out.

[Pipefitter]

I can definitely say,that in building my boat,any time I "saved" any money on purchasing material,I paid dearly in extra epoxy and fairing time. After it was all said and done,next time I will hold out for the best I can get. I never intended to cheap on anything but availability of good material here in this overgrown cowtown I live in is scarce. Any vendors that do stock it wont even deal with Peter Public. I went to Dixie ply here in Tampa and you would have thought I was after homeland security clearance immigrating from Iraq.I had to go thru my company,tax # and 20 questions. After all that,the product was crap. Not a rant here but please,anyone that is building a small boat,you are not going to save any money buying cheap materials. The old saying.."there is no such thing as a bargain" holds most true in building a boat. Using lesser than great will take all the enjoyment out of building it.

[Ken_Potts]

Noel,

If you look at the end of a board and the rings are running roughly parallel to the face of the board it is flat sawn (or plain sawn). If the rings are running roughly perpendicular to the face of the board it is quarter sawn. I believe rift sawn is somewhere in between - Someone who knows better please correct me.

[Barry Pyeatt]

Plain sawn lumber is vertical slices taken off of the outside of the log as they occur. The rings run across the width of the board and when you look at the flat surface the grain lines can and do run anwhere and everywhere.

Quartersawn wood is taken as a horizontal or vertical cut from any of the quarters of a log. But with the grain running at about a 45 degree angle across the width of the board. The grain lines on the flat surface tend to be straight (er) and run the length of the board.

Vertical grain or "riff sawn" board are taken dirctly across the middle secion of the log, either horizontally or vertically. DRaw a vertical line down the middle of the log or horizontally across teh middle and take the board from there. The grain runs literally vertical across the width of the board. This is the most expensive cut since it is harder to cut up a log this way and these would be "select" cuts out of the log.

The vertical grain boards are generally very straight grain with few if any defects.

The quartersawn boards are generally very close to vertical grain in quality of appearance. The advantage to quartersawn boards is that when you use fasteners thru the board, you are still going cross grain for maximum holding power. (When you go with the grain, it tends to split and be a weaker holding ability.)

With plain sawn lumber, the wood will curl (cup) as the wood drys out and shrinks. The smaller (inside) rings pull the wood around them and end result is the cupping effect. This is ordinary construction grade wood in the softwoods. In hardwoods it is the highly figured wood with the wild grain patterns.

In woods for boat building we look for tight grain, every close rings with even consistency between them. Higher counts per inch of growth rings. This tree grew slowly, shaded by others and didn't see much difference between spring/summer/fall/winter growth patterns. This is highly desirable for consistency in materials. This generally comes from older growth trees.

In todays market, we see young trees, plantation grown in many cases with maximum growth per year so that they can bring them to market much quicker. "Sustainable yield forestation." The growth rings are very wide by comparrison and there is a huge difference between the spring/summer/fall/winter growth periods. So the lumber is inconsistent across the growth rings, tight in one area and wide and then tight and so on.

This is fine for the construction trades but not so desirable for boat building where we want maximu holding power and strength in the materials.

The process at the mills is pretty straight forward, if it is a premium log, it gets cut for premium lumber. More expensive process and selection on the green chain. More quality control and care in handling all the way thru to the retailer.

If it isn't a premium log it gets cut into studs and construction grade lumber. Sorted by grades and kiln dried. Good stuff gets higher costs, loser quality grades get sold on the market as "Stud grade".

Wider boards, such as 12" wide material are selected from the larger logs and carefully cut so as to maximize the number of boards that can be produced. Some, (most) are plain sawn, some are quartersawn but very few are vertical grain. Simply because there are fewer premium logs available today.

[Howard]

This Internet thing is great. A couple of sites to look at:

http://www.allwoodwork.com/article/woodwork/plainorquartersawn.htm

and to expand on that.....

http://www.bchardwood.com/glossary_sawn.html

and....

http://www.hoganhardwoods.com/hogan/pages/technical/Technical_01/lumbersawing_01.htm

I find from this that I have been using these terms incorrectly. The lumber I have been referring to as quarter sawn is actually plain sawn. But if you rip down a few inches off one side of a larger plain sawn board, it will resemble the straight grain pattern of quarter sawn. The whole board won't, but a portion of it will.

[Barry Pyeatt]

Good links Howard. Those links should be placed into our FAQ section. Along with the link to Glen-L.com. The discussion on appropriate woods for boatbuilding is well worth the reading and bookmarking for anyone considering building a boat that they expect to last a long time and have few maintenace issues with materials.

Yes, it is possible to get good stringer stock from lesser grades of lumber by cutting plain sawn wood into narrow strips. Some of the grain will look like quartersawn and some will look like vertical grain. But the clincher is wether or not it is straight grained lumber.

Unfortunately it usually is not. The grain doesn't run the length of the board when you look at the narrow edge, it has a lot of run out on the edges where the growth rings literally run off the edge of the resultant strips, some of it dramatically as you get to areas around knots or bends or changes in the character of the log at that point.

The issue with grain runout is that that point is the weak point in the resulting strip of wood. If you place a fastener at that point the strip will likely break or crack when you bend it. So trying to use them as stringers can be problematic but not impossible .

You would want to again pick the straightest grain lumber possible with as little runout of grain along the edges. Then orient the stringer cuts on the board so that you can drill (fasten), thru the layers of grain where possible. With quarter grain stringers you can attach from different sides of the stringer and place your fasteners thru the grain from different directions with planning.

The biggest advantage is that the stringers will take a good fair curve along a long distance. With little runout of grain on the edges you have good holding ability and sound construction.

These are some fine points to consider, but this is why wood selected for boat building is a bit of a fine art in itself and the primary reason why selected woods are so expensive. They are premium cuts and selections from the entire market.

We try to find as close to them in quality at our neighborhood "Big Box" stores and accept what we can find. But a good lumberyard will have or can get what you actually want, and they know the difference. The guys at the "Big Box" stores generally don't even know what a board foot measurement means. Let alone differences in grading or how lumber is cut.

Picky, yes, I'm picky when it comes to selecting the materials that I am going to put into a boat. I am going to be out on the water with it, I expect it to last a long time and since the actual cost of the lumber is the smallest part of the overall cost of building, I will go thru a pile of boards and pick out what I want to use. But I always restack the rest so it is neat. :wink: That way I am welcomed back by the management and can go thru more stacks to pick out what I want. And while at it I generally neaten up the materials around it too. 8)

[Barry Pyeatt]

Here is a link to a great article on ring counts by Bob Smalser.

http://www.woodcentral.com/cgi-bin/readarticle.pl?dir=smalser&file=articles_404.shtml

It may help you to look at the end of a board you are considering in a whole new way. :shock: :roll:

This is one of the reasons I haunt the Recycled Wood dealers. The boards may not look as pretty on the surface and may have a few nail holes etc. in them but the quality of the actual lumber is usually a lot higher than the new stuff you find at the "Big Box" stores or anywhere in construction grades of lumber.

A good example would be two 14' 4X4 Douglas Fir posts that I found that were dirty, painted over, dings and dents in the sides but when you look at the end grain it was apparent that this was vertical grain premium stock from old growth trees. The grain count was over 20 per inch and consistent across the entire post. I picked them up for less than Stud grade prices at the local Lowes or Home Depot. I was going to cut them down anyway to make a mast and two booms for other jobs so I didn't care what they looked like on the surfaces.