Thread: Wood Selection in USA for a GIS

I don't have issue with your choices, though the centerboard and rudder staves should be heavier then cedar (in my opinion), I'd use Douglas fir or the SPF available from the big box stores. These are denser and stiffer then the cedar.

Yes, the clear fir we usually see around here is overly strong for the spars. It's also on the heavy side, being about 30% denser.

With epoxy encapsulation 1/2" staves shouldn't have an issue with checking, they're just too thin for real problems. Inside a laminate like the foils, also not an issue.

Originally Posted by Rickd

-Chinelogs, inwale spacers, centrecase spacers and framing = WRC
(available as 1" * 4's up to 18' length) $1.15 / ft.

-Centreboard staves, rudder staves, stem = WRC 2" * 4"

The recommendation at Seafarer for the mast, boom, and yard is vertical grain CLEAR FIR.

QUESTION: would the "clear fir" that we normally get in the Southeast be strong enough to use for MAST, BOOM & YARD built with dimensions as per the GIS plan?
(mast stave thickness of 12 mm; boom & yard 40 mm round)? My preferance was White Spruce - but this isn't available via Seafarer.

CLEAR FIR is also recommended for gunwales, inwales, partners, knees, transom top and frame.

The hardwood available for gunwale cap, foil leading and trailing edge and bottom skid = white oak.

A little concerned re the prospect of clear fir checking?? Might need to travel up to northern Florida (Par's neighborhood) to locate some acceptable White Spruce for the spars.

No problem with fir checking.

W Oak is nice but you need to glue it with G-flex (West System) or T88 (System 3) or another glue that can deal with W Oak (Polyurethane glue may be ok but look into it). W Oak has a bad rep for glueing properties. (I'm using really nice tight grain DF for the gunwale cap.) You will like Spruce better for spars and if there are small knots you can replace them with plugs. If you find good spruce, use it for the foils, too, or offcuts of the DF.

I think you're fine with your list, with a couple of notes.

First, Paul is right that wrc is on the light/fragile end for foil staves. I really like the scheme of using it for most of the staves, but using something denser/tougher for the first and last (foremost and aftmost) staves. That's where the vast majority of the abuse will occur.

Second, I agree with Clint that there are lots of reports of gluing issues when using epoxy with white oak. I personally have never had a problem - either with West System or Raka epoxies, but some people clearly have. His recommendation is a workable one... or you could choose a different species. Anything dense and tough is fine. It's a very visible part of the boat... so you might want to go with something that's pretty as well.

Sounds like you're narrowing it down nicely. G'luck!

Just returned from my "local" lumber yard - no spruce outside of #2 construction grade material with major knotting. They DO however have IPE in lengths up to 12 feet - to use for gunwale caps, skids, and a centrecase cap...and also for the leading and trailing edges of the foils. I believe I will use clear fir for the foils since it so readily available in Miami. Spanish Cedar is available as well - and might be nice for the transom top and frame.

They also have clear pine - that might be suitable for the mast ?(thoughts on pine?) - but I am still seeking out a source of some nice spruce. But at least I was able to pick up a piece of fir to practice with my new Wood River block plane. It was "partially sharpened" by the Woodcraft store rep - who is a "plane tuning specialist" - he is giving a 4 hour sharpening and tuning class this Saturday so at least it is a start of making some kind of wood shavings - even though not on any GIS final piece.

Part of this entire process is becoming familiar with the characteristics of the specific woods and trying to make a reasonably informed decision at the end. Thanks for your comments - they have been very helpful to a true 'wood' rookie.

I'd shy away from pine for masts. The douglas fir is just peachy. While spruce is superior in strength to weight ratio, I actually like douglas fir better for small boat spars. On boats like a GIS, the spars get handled a lot more than on a boat with a fixed, stayed rig (standing rigging).

The fir is definitely more rugged, and will stand up to the inevitable abuse better than the spruce. It's heavier than the spruce, but it's also stronger. To a substantial degree, the extra weight can be offset by reducing the scantlings somewhat - which the higher strength allows.

In the case of the GIS, though, Mik has called out, and engineered for, douglas fir spars from the get-go. No adjustments necessary. We built the solid mast - before Mik came out with the hollow version. I'd strongly recommend going with either the hollow, box-beam mast that he's designed... or doing a hollow, birds-mouth version of the round stick.The added weight aloft of the solid mast on a doryish, lightweight hull makes a big difference.

Aardbordg. I appreciate the comments. I have come to accept the inevitability of my geographic location - I have access to Okume (perfect), Spanish Cedar, WRC, IPE, and clear fir - so that's what I'm using...where appropriate. So ends the fruitless search for spruce.

Spars (hollow box mast), boom & yard (rounded as per Mik's plan) = clear fir

Seafarer Marine suggested "vertical grain clear fir" for the mast - they get it in 2" * 6" lumber and it is - beautiful - but expensive. The alternative is to simply pick up 1" * 4" * 16' clear fir, cut to shape, plane down to 12 mm (1/2 inch) thickness, and not worry about "vertical grain". Clear fir 1" * 4"'s are $1.05 / foot ($67.20 for 4), vs $190 for ONE vertical grain 2" * 6" * 16 (and you would need two for the job - 4 boards).

Boom & yard - would come from ripping a 4" * 4" * 16' to get two pieces of square stock 1.75 * 1.75 that would then be "8 sided" and then rounded and tapered.

I plan on using the same clear fir for rudder & tiller staves with IPE leading and trailing edges.

Well - back to revising / updating my materials list!! Thanks again. Rick

Howdy,

Vertical grain is not necessary. The idea was to avoid cupping breaking the joins with drying out or water absorption. This is not much of a problem with an epoxy coated mast.

Michael

Sounds like Rick has a plan!

Rickd

I'm building a GIS in St Pete so my lumber sources are pretty similar to yours.

Used Home Depot Doug Fir for the birdsmouth mast and am very happy with it. They have a decent pile of the stuff so you can pick through it and select the nicest lightest boards. My mast without any hardware is right about 20lb so not too bad and the cost was about $70.

I just recently got Joubert Okoume from Boat Builder Central in Vero. Nice guys and the ply is beautiful.

I used Lowes WRC for the foils. Again they have good stock so you can pick through it. Absolutely clear pieces are not necessary for the foils buy why not if all it takes is sorting through a bit of wood.

But man IS that vertical grain stuff pretty!! A guy had just stacked 50 vertical grain 2" * 6"'s in his pickup truck. Each board was identical. Quarter sawn / vertical grain - looked like it should have been in a lumber exhibit. Lowe's in Fort Lauderdale had a very poor selection of lumber. I'll get any WRC I end up using at Seafarer Marine - since they sell / source primo lumber for the yacht building trade. Outside of a little bit of WRC and the Okume, my local lumberyard (Shell Lumber) in Miami has a good selection of clear fir, IPE etc. They even have a 1/2" * 4" clear fir - but the actual measurement of the thickness, looks to be 1/16" shy, so I will probably go the route of buying the 3/4" (18 mm) stock, and mill down to a true 1/2" (12mm). Now that I know what I want to do it will be the "roundtuit" part. Start a new job on Monday (just switched - and took a week off in between), so I will be quite focused on getting established in the new environment - some travel - domestic and Latin America (Peru, Guatemala). Nice to know a GIS is being built in St. Pete. I might take a run up there some time to chat about the boat, plans, and process. Thanks. Rick, Miami, Fl.

Hi Rick,

If you are excited about the beauty of a piece of vertical grain Fir ... then it MUST go on your boat. No Argument from me!

MIK

CVG doug fir is nice stuff. I built a 30' power boat and the project manager bought doug fir for all of it. The really vg stuff splits REALLY easily. I watched a boat go out in our local "Raid" with a beauty of thwart/partner with DF. I bet the guy looking at it with me that it wouldn't last the day. End of the day, the owner came back with a split right along the grain. Used correctly, that unidirectional grain can be useful. The other trouble is that the splinters DF creates are really nasty sometimes. I came home with a splinter through one side of the fleshy part between thumb and index finger and it came out the other side. They were not all that bad and you won't be using hundreds of BF of the stuff. I really like DF, maybe the best all around wood you can use in a boat.

Point: if it makes you excited, use it!!!

Rick, Go look at Simons birdsmouth mast...it is beautiful (I have not seen it except on his blog)

-_Clint

Cypress Things by J & S Cypress Sorrento Florida

These guys mill Florida cypress and make beautiful stuff....seems like Cypress works for them, perhaps because they have bigger diameter pieces.

I've got a pile of Cypress I was going to use for frames, chine logs, foils, but I am more careful after PAR's explanation. Choosing the quarter sawn edges of the boards should help and inside the foils, locked away under epoxy and glass (Like we in the NE US are locked away under snow and ice) things should be just fine.

--Clint