Thread: Goat Island Skiff (Chile) - Construyendo un pequeño bote de madera en Chile

OK, here we are in Santiago (Chile)... and with a lot of enthusiasm we have decided to build the GIS with my friend Ignacio. We have been sailing a J24 for some years now, but we wanted a small boat to sail in lake near Santiago (Rapel). So we chose the GIS and invited our families to participate in the project.

The first big issue: where we should build the boat? As I live in an apartment building there is not enough space. Ignacio's house is bigger, but the carpark is full with motorbikes, bikes, cars and other stuff. There was no place... but I remembered my mother-in-law owned an old house in a nearby suburb which is used as a "pension" (bread and breakfast) for university students and it has some space in the backyard which is use to make cotton mattresses, the original family business (they were italian inmigrants to Chile). After we visited the place we thought it was ideal, there was a small vine, that we will cover, and enough space.

After some time we found some good local wood suppliers and an epoxy supplier.

I got in touch with Michael who has been very helpful in sorting out issues with epoxy and I'm sure will give us advice in the future.

We will start building the boat on the weekend and keep frequents updates on our progress.

Cheers mates!

JC.

Originally Posted by Juan Carlos

This is the first GIS in Chile and my first boat too!

Don Juan,

Welcome! I see you're just starting. I also built with a friend - and my two teenaged sons. We all had a great time. I'm sure you will too.

We all love fotos, if you can supply them. In return, I offer these images of "Sisu", the first GIS in the Americas. She's the baby blue boat in the various fotos:

http://s156.photobucket.com/albums/t...t=PICT3090.jpg

http://s156.photobucket.com/albums/t...t=PICT3183.jpg

http://flickr.com/photos/arbordg/288...7607440686952/

I´ve got the GIS plans from the Duckworks website and
now I´m planing to start building the first GIS in Chile with some friends.

I´ve got all the woods with some "local adaptations" which I expect not to
cause major problems.

The biggest issue here in Chile is with the epoxy stuff. As amateur
boatbuilding is not very popular, I have had to use the local resources and
advice from producers and sellers. One of the problems is they are offering me
three products: an epoxy adhesive, a "marine varnish" and a "lamination resin"
(I hope not to get lost in translation). According to my understanding from
your website and the plans, we should use the varnish in every piece, except
in the faces which are going to be glued toghether, but how many layers should
we use? and I´m not very sure what we should do with the hull... should we put
the varnish first as a "primer" and then the "lamination resin" (again, how
many layers?) once we put the fibreglass tape on the chines? They say the
lamination resin will be hard in 45 minutes... I think that is too quick isn't
it?

Anyway, there is still time until we reach that fase of the GIS construction,
the woods will arrive on thursday and we will start marking and cutting on the
weekend. I hope you'll be able to give us some advice.

I was very happy to see the GIS was an Aussie design. I'm a paediatric surgeon
and I've been back in Chile for a year now, after living in Australia for
three years (Melbourne and Sydney) while I was training. I worked in the Royal
Children's Hospital in Melbourne and the Children's Hospital at Westmead and
it was a very good experience. I left a lot of good friends and I've always
considered Australia as a second home.

Best regards and muchos saludos,

Juan Carlos Pattillo.

Hi Juan Carlos,

Nice to know you have an Australian connection. I am originally from Sydney so I probably know many of the places that you do.

It sounds like the wood and plywood choices will be fine.

I think there is more to talk about with the epoxy, varnish and lamination resin. And to make sure we understand each other on these technical matters!

OK - now epoxy comes in different forms. The best one is a liquid resin and liquid hardener that get mixed in some ratio ... usually between 2:1 or 5:1.

Common types are WEST, System 3, marinepoxy,
Just found a guy building model aircraft in Chile using WEST System epoxy .. you could join up to the forum and send him a message by clicking on his name. He is making a mistake with his method too ... you should not dilute epoxy. But he will know where to get it from.
http://www.rcsailing.net/forum1/show...93&postcount=2
Also this one http://gallery.bateau2.com/forum/vie...ighlight=chile


this liquid type epoxy is used for all three main building processes
1/Gluing .. add a special powder for high strength gluing (or you can use VERY fine timber powder from an abrasive sanding machine.
2/ Fibreglass taping (chines) or covering (the centreboard or rudder) - no added powder
3/ Coating all surfaces of the boat to reduce maintenance - no added powder. The epoxy still needs to be varnished or painted to protect it from UV light. epoxy coating can be done with the epoxy using the wet on wet process

Some epoxies are not liquid but are prethickened so you don't need to add a powder. These do not perform as well as the liquid ones.

Varnish is for finishing only and does not have a structural adhesion to timber. You have to let each coat dry properly before adding a new coat.
Paint works in the same way to protect teh epoxy from UV light. You do not pre coat the boat with paint or varnish but they are used once the parts are all assembled to protect them.

Those above are the best materials to use.

I suspect the "lamination resin" is polyester ... much inferior to epoxy. There are two ways it can be "hard" after 45 minutes. It can mean it is completely hard and could be abrasive sanded - if this is the case it is polyester resin which does not adhere to wood very well. However if hard means that it is not liquid enough to apply after 45 minutes and will be hard the next day then it is probably an epoxy base.

Another way to know is the amount of "hardener" or "Catalyst". If the resin to hardener is a ratio like 2:1 or 3:1 through to about 6:1 it will be an epoxy. But if it is only a a few ml per litre then it is polyester resin

Polyester should be avoided because it does not adhere to wood very well, but it is better than using nothing at all for glass taping.
Epoxy adheres very well.

If you understand this you need to check availability of the liquid type epoxy. if it is not available then you need to contact me again to look at some other alternatives.

Hi Michael,

Thanks for your reply.

First of all let me tell you that it hasn´t been easy to fix the problem with
the epoxy...

The Chilen guys that used epoxy got it from a Hobby shop in small quantities.

The international orders from US are expensive to consolidate in the country.
They have been nice to me, but I don´t think thet is the best option.

The local epoxy supplier offers me an "Epoxy lamination resin", it is not
polyester (I`ve check it), it is 100% epoxy. The two components are used in a
1:2 ratio and the resin is liquid. It takes 30 minutes to 1 hour to be hard
(to touch), but the complete time to dry is 4 hours and then it can be sanded.
According to their specifications the product has a high level of solids, it
is colorless to ambar and it has UV protection. It is recommended for
lamination with fiberglass, carbon fibre or kevlar. It is resistent to
chemical products with a good mechanical resistance and flexibility. It
doesn´t need any solvent. I think this product is close to the epoxy resin you
use.

We were discussing about the issue and the fact we`re using 6mm marine plywood
(could`t get the gaboon typo) and maybe we should cover the whole hull with
fibre (from outside of course) and use the epoxy lamination resin ofered by
the local supplier.

I will be very happy to hear your opinion.

Muchos saludos,

JC.

Howdy JC,

This resin sounds like it may have a fast cure - we generally cannot sand until the next day ... but everything else makes it sound fine .. even excellent.

So I hope you will have enough working time. Maybe buy a smaller container for the initial gluing and see how it performs.

You will need the right sort of powder to make it into a glue. The powder must be a fibre at the micro level and not round. A good test is that if the epoxy with the powder in it sands easily then it will be weak. But if it is REALLY hard to sand then it is strong. If you cannot find any powder then you can use VERY fine wood powder like from a sanding machine. Make sure it is a species of wood that is easy to glue though!! Not teak or another oily timber.

I would not cover the outside of the boat with fibre - it adds a huge amount of weight. Glass is 8 times heavier per volume than wood. There are many people who think it adds negligible weight .. but they have never measured anything!!!

If your plywood is made of 5 layers (veneers) of timber then it will be fine to build the boat as designed. If it is only 3 layers I would recommend putting glass cloth on the bottom only and coming around onto the side panels of the boat by 25mm. This will make the bottom very strong even if you use a very light fibreglass cloth for this purpose - 75gsm (grams per square metre) is plenty and you would not need to use the glass tape. The sides don't need any extra strength.

If you get a smaller amount of epoxy and it gives you enough time to glue the framing to the bulkheads, then it will be OK for the building of the boat. There is a lot you can do with procedure as well to give yourself more time if the epoxy is fast. Do they have a slower one - might be worth asking?

Give me lots of feedback about how you are going - even on my forum below. and I will try to work through problems (if any) with you. The forum is good because the info will be there for more people. I think many building all sorts of boats would be interested in the epoxy supplier for example.

Best wishes
Michael

I have attached the epoxy specification below.

Hi Juan Carlos,

Found the website and contact details for the epoxy supplier in Chile

[email protected]

BODEGA: El Nevado 6, Colina CASILLA: 40 Colina

FONO: (56-2) 745 3247

Thankyou

Michael

Hi Arborg, Very nive photos of SISU. It looks like an awful weather though!

I´ve just got the epoxy adhesive, the people from Epothen sell the adhesive (two pots) appart from the resin. Tomorrow we will see what happens.

Saludos,

JC.

Originally Posted by Juan Carlos

Hi Arborg, Very nive photos of SISU. It looks like an awful weather though!

I´ve just got the epoxy adhesive, the people from Epothen sell the adhesive (two pots) appart from the resin. Tomorrow we will see what happens.

Saludos,

JC.

Don Juan,

Well, I can't say I haven't sailed in that sort of weather. We do live in a temperate rain forest here is the Pacific Northwest. However, in this case, all the fog is an illusion created by the fogging of the interior of the camera lens. The final foto was taken with a different camera, and is more representative of the actual weather. With the kind of winds we were having, the fog wouldn't have lasted long.

I look forward to seeing your fotos and hearing about your build. Let us know if you have any questions as you proceed. Not only do you have Mik, the designer, here - but you also have several folks who've already built a GIS - or who are ahead of you in the process.

Here's another foto you might enjoy. This one has friend Jerry in Sisu in the background, and me sailing "Shredder", Puddle Duck Racer #77 (with a Storer-style balanced lug rig) in the foreground. Between us, you can see the line where one passes from the windy open lake area and the protected wind-shadow of our campground. That's why Sisu is still moving briskly, while Shredder is just drifting toward the beach.

http://s156.photobucket.com/albums/t...t=PICT3125.jpg



"Every man is guilty of all the good he didn't do" -- Voltaire

A nice day in Santiago to start building the boat...


But the problems started... The 6mm marine plywood we bought was a poor quality one. We didn't check it before delivery. But, as you can see, the plywood has only 3 layers.




There were several knots of different sizes, some of them were not to bad.


But there was some big cracks and we think that is not acceptable to build a boat



and evenmore, some cracks were filled with filling paste


The plywood was probably damaged during the transport


Under these circumstances we decided not to do any cut and to return the wood or see if we can change it tomorrow.

We are facing the local reality again, and I think it will be hard to find very good quality 6mm marine plywood. Maybe, it will be a little bit easier to find a good 9mm plywood (not sure if the "marine" type) or see if we can find a better 6mm marine plywood with less knots, but I don't think it will have the 5 pl.

The rest of the wood for framing, chines, etc looks well (we got it from a different place)

The good thing is that we set up the place for the boat and it looks very nice. Hopefully we can start cutting soon.

I will be very grateful to hear some expert opinion and advice.

Cheers,

JC.

JC, Can't help a lot except to say that you made the right call! You're right, you must have 5 layers.

Are there any boatbuilders in Chile whom you've contacted?

Cheers,
Clint

Howdy Juan Carlos,

this is not very good quality plywood. the three plies (veneer layers) is a problem for the bottom of the boat and the seats. It may be OK for other areas.

some of those repairs are already falling apart.

Best wishes
Michael

Thanks Clint and Mik.

I found a local producer of special plywood. They have a 5 layers 9mm plywood of A/C quality, that means only one face with some knots. (www.infodema.cl)

There is no 5 layers 6mm plywood in the country.

This time we will chose the wood ourselves.

I will let you know what happens in the next couple of days.

Saludos,

JC.

Hi Juan Carlos,

The new supplier sounds much better.

If you cannot get 5-ply there are a couple of simple changes that will prevent any problems.

If the plywood looks good can you put the supplier details here too.

Someone will be able to use it for sure!

Great pic of Santiago, by the way!

Thankyou
Michael

Hi friends,

We have the new plywood and it is very good. Quite expensive though.

Finally, I got it from Sodimac (www.sodimac.cl) under "materiales de construccion - maderas - maderas contrachapadas - terciado marino nativo". Sodimac is like Bunnings Warehouse in Chile.

The plywood is rare and they have it in some few stores, so I ordered it through internet... they found it and delivered it for me.

(http://www.sodimac.cl/cgi-bin/ncomme...TOAMPLIADA2=NO)

So I've started marking out the panels today. Sorry I didn't brought the camera, but when we start the cutting on the weekend I will show some pictures.

I have a small jigsaw which I think is ok. for the plywood. Do you use a baten as a guide or just freehand? Is it better to get a circular saw? Do you leave a couple of mm and then plane them down to the lines isn't it?

Will keep you updated, cheers,

JC.

With ply I use a jigsaw because it is easier to follow curves and I freehand to about 2mm and then use a block plane to get down to the line. I know others use a batten, but they still give themselves a little margin which needs to be planed off. Circular saws are difficult to use to cut curves and tend to splinter the plywood veneer. Even with a jigsaw the veneer can splinter.

One way to try to prevent this is to put masking tape on the line that you are going to cut (ie just outside the line you have drawn) and use a blade with the teeeth angled so they cut when the blade is going up towards the top surface of the wood.

On cutting the panels: my first project all I used was a jigsaw, a sharp block plane, and a nice douglas fir or pine batten. That is all that is needed. Layout the shape, spring a nice straight batten through the points, make the batten fair which may mean not going exactly through a point or two, and cut as close to the line as possible with the jigsaw. I recommend a clean cutting wood blade or a coarse metal cutting blade. Then with the panels still clamped together, plane to the line and be sure to check frequently that the planed edge is kept square through the process (something many people don't check!). Then sight the lines and if they look fair then you are all set.

I cut my planks differently now. I use a batten offset and run a skilsaw down the batten, the base of the saw running along the batten, and I cut the panel out direct right to the line, no planing. Depending on my mood, I might put the batten right to the line, cut proud with a jigsaw or a skilsaw, and then flush cut the panel with a router.

John Brooks, a friend in Maine who write a fabulous book on building glued lapstrake plywood boats http://www.brooksboatsdesigns.com/bigSStwelve.html, has a great technique too.

But all you need is the batten, a square, a jigsaw and a plane! Just check that the edge is kept square! This is a fun way to do it, if a little time consuming.

Cheers,
Clint