Thread: GIS Brazil - Materials

Hi Ciao,
Michael is also on the GIS Facebook page almost every day. https://www.facebook.com/groups/GoatIslandSkiff/ along with 250 other GIS builder/sailers/wannabes who are glad to answer questions.

About wood, my take is that good plywood (gaboon/okume of good quality) is essential for a quality boat so try to source that. People who tries mail-order wood seems all pleasantly surprised of the quality so if you can't find it locally that might be an option. For the solid wood WRC= something light straight and knot free, and spruce/douglas fir or whatever the plans specify = something a bit more substantial like whatever is the traditional boat building wood of your country. For wood, strength is very much proportional to density. Google the density of your local species and choose based on that. Straight and knot free is essential for a headache free build though.

Good luck with your build and please let us follow your progress!

Pontus (on his second year building and not even half way through)

Hi Scoot, thank you for the answer.
About the ply, is what's giving me the most problem... It's almost impossible to find it in the length needed. Here in Brazil the standard measure is 220cm, in the plan he asks for 244cm... Even if I choose to go with the smaller ply (and glue another part), the only marine ply I'm finding is the cheap kind... The ply vendors here doesn't have the slightest idea what's gaboon/okume.
So when you say a good quality ply is essential, what exactly do you mean? Will my boat sink or rot?

For the WRC I choose Tamburi, a light wood I heard some people said is good for boat building. For the spruce/douglas fir I think I'll go with Freijó and/or Cedro Rosa, bought I think are used in boat building.

Here in Brazil we have more heavier woods than lighter ones, so traditionally boat are built with heavy - and durable - woods. So what is more important when choosing wood: the weight, the strength or being able to resist water? I know we should look for all three, but what do I prioritize?

Thank you again,

Caio

Good ply is light, void free ply. Gaboon is something like 30% lighter than ordinary marine ply. Since the ply makes up a big part of the total weight of the finished boat, savings here makes a difference. A light boat is a fast boat, and also much easier to handle on land. Therefore light timber is also a good idea. Rot resistance is not important at all since all wood will be encapsulated in epoxy.
The boat will float the right side up whatever wood and ply you build it out of. The consensus seems to be that as long as you spend som much money and time anyway, it's a good idea to choose the best available materials. Epoxy, sails, lines and blocks will make up most of the cost anyway. I can't remember any recent Brazil GIS build, but other south american GIS builders (Uruguay, Guatemala) have had to source the ply from quite far away if I remember correctly (perhaps even from the US?), which of cause is expensive. It's very easy to spend other peoples money, if costs is a concern go with what you can find, if not mail order the ply. I live in Gothenburg, Sweden, and here as in most countries it seems, no ordinary wood store new about gaboon ply. The only specialised boat wood seller catering for amateurs in the country wanted a huge pile of money for it, but insistent googling found a local wholesaler catering for our local boat building companies (Najad, Hallberg Rassy, Malö) who sold me a couple of sheets for a very good prize.

Cedro Rosa translates into Red Cedar, doesn't it? Might be the same thing as WRC? (Or not). When substituting WRC go for light straight and knot free. The gunwales and spars needs something quite strong, but not too heavy. Things that traditionally is used for spars in your part of the world will be good me thinks.

Good luck sourcing the wood, it can be a bit frustrating but also rewarding when you find what you have been looking for.

Pontus