Goat Island Skiff or Mollyhawk

[Zaneroni]

Hi
I'm about to build my first boat and have been going back and forth trying to decide on the design. I have 2 boys, 11 and 12 and a dog , the wife will show up every now and then but she will not be a regular deck hand.
We have a couple of fishing aluminum boats and wanted to build something that will offer rowing and sailing capabilities. I narrowed my search down to a couple of designs:

Goat Island Skiff - Michaeil Stroer
Mollyhwak - John Welsford

Being my first build, I want to work on something that is fairly easy and will forgive using exterior plywood vs more expensive marine ply.

I have read ceveral articles about both desgins and the people that have those boats seem well pleased by them and their performance.

The kids want be to build the Goat island so they can move around in it safely when they are fishin ( but this is what the aluminumboat is for!)

I would appreciate your input.
Thanks

[Thorne]

Welcome to the Forum!

First you'll want to update your location using the USER CP link on the upper left of the page -- saves a lot of typing. Also tell us what waters you plan on sailing, and conditions for same -- offshore or local duckpond?

Second, you will find that your idea of using exterior instead of marine ply is not a good one, and will seriously derail any discussion of plans.

Third, if you are looking for a sail & oar boat (one that rows as well as it sails), why consider Welsford's Mollyhawk which is a pulling (row) boat only design??

Now to issues 2 and 3:

Using exterior ply is a false economy, as the only way to make the boat last is to cover it with fiberglass and epoxy, thereby increasing the cost and weight. Unless you intend to seriously limit the use of the boat to only a few seasons and then destroy it, you'll be putting yourself, your boys, or subsequent owners in a world of hurt using the rot-prone exterior ply. If you live in Oregon the Coots have an annual boat-burning party which features boats built from inexpensive materials.

The Goat Island Skiff (GIS) has quite a few fans here and at least one designer-approved builder, and sounds to me like it would meet your needs exactly. It can row, sail, and take a small outboard.
http://farm4.static.flickr.com/3629/3395269065_cd5cbd999e_b.jpg

http://farm4.static.flickr.com/3654/3464094416_faa898745e_b.jpg

[Cuyahoga Chuck]

I have to give you the quicky evaluation of US made exterior grade ply.
It's all made from softwoods like fir and pine. That means it's got bands of early wood and late wood that are of different hardnesses so any surface preparation like sanding will make the grain stand out more than it already is. It's a big drawback if looks matters to you. The exposed grain can be faired out but it takes time, involves a lot of sanding and will increase the weight of the boat markedly.
None of the plywood made in the US is made to a common standard. Various regions where ply is produced have their own associations which make and enforce quality standards. None of them press their members very hard because they can all sell everything the make. Most of the exterior they make is full of flaws like ragged veneers that create numerous voids when they are used as interior laminates. This can produce weaknesses and places that can trap moisture. Go to any bigbox lunber store and look at apile of exterior ply. You'll see gaps along the edges of every sheet. There are a lot more you can't see.
Our softwood plywood is all about 1/3rd heavier than a similar panel in BS1088 okoume. If you add that to your inexperince in S&G boat construction your 130 lb GIS will probably be closer to a 200 lb GIS.
I havent seen the GIS plans but if it calls for ply thinner than ¼" there is no suitable US ply.
There is more. If your ex-grade ply is fir it will eventually check. I.E. all the exposed surfaces will become covered with little splits in the grain and ruin the finish. The only remedy is to glass all the exposed surfaces. This wou,ld mean more weight yet.
Using the expensive imported marine grade ply will cut the amount of backlabor significantly so there is a payback for spending the extra money. This better ply has none of the drawbacks of exterior grade. It's structually better, and has more veneers in the thinner panels, and has exterior faces that are of furniture quality.

[Daniel Noyes]

Wow! don't tell that to the 4 Chapelle Banks dories built by Triton Highschool of exterior grade ply, and used and abused by students and staff for nearly 40 yrs.
... seems like plenty long for a home built boat.

if your going to payfor expensive foreign ply and for shiping it all over the world why not get superior American made Marine fir, it is stronger than same thickness okume and doesn't need to be treated with anti rot chemicals... I'm not crazy about inhaling fungicides as part of the experience of building a wooden boat.

[Tom Lathrop]

Wow! don't tell that to the 4 Chapelle Banks dories built by Triton Highschool of exterior grade ply, and used and abused by students and staff for nearly 40 yrs.
... seems like plenty long for a home built boat.
.

40 years ago you could walk into a builder's supply and buy A/B or A/C exterior fir ply that was often as good as the best modern marine grades. Today, that is apparently all gone and replaced by stuff that can best be called crap. Most of the old line manufacturers don't even make it anymore. Even the BS1088 and BS6566 Standards are no longer supported by other than the plywood makers reputation. There is no independent inspection and grading by the originators of the BS standards.

Still, skimping on the plywood is poor economics.

[mcdenny]

Another vote for the good stuff: You are presumably building a boat because you hope to enjoy the construction experience. Okoume or Meranti ply will be much nicer to work with and both will take a finish well. Fir, even marine grade fir, is a royal PITA to finish and will check no matter what unless fiberglassed.

I bought some exterior fir (not for a boat) from Lowes on a rainy day - after an hour ride in an open trailer it started to delaminate.

[Clinton B Chase]

Hi

Goat Island Skiff - Michaeil Stroer
Mollyhwak - John Welsford



These are two totally different types of craft, one is a sailboat the other a rowboat. The GIS is pretty easy to row by the way because it is incredibly light. It would be a more stable platform. If you want a stable rowboat for fishing the MSD rowboat would be better. If you want to sail, the GIS is better. Decide what kind of power you want to use: motor, sail or oar.

Clint

[Clinton B Chase]

I do wish to add, that if it is rowing you want to do, than Welsford really knows how to design a proper rowboat. Then Mollyhawk WOULD be the one.

[seawardadventures]

I had a San Francisco Pelican for about 15 years. she was built of marine fir covered in dtnel and epoxy. She held up well in spite of my abuse and is sailing around the Washington D.C. area. I sold her to a guy in the Dept. of State.

My more recent experience with marine ply comes from working in a plywood mill here in the pacific northwest. The place was run like a sweatshop and the crappy attitude of the management showed in the quality of the product. we mostly made exterior doug fir, T-111, and MDO but also ran marine ply on special orders. The stuff was a joke, poorly graded and the core was no different than the stuff that went into C grade exterior panels.

I am looking to build something along the lines of what you are considering. The Goat Island Skiff happens to be on my short list. I will bite the bullet and use Okume. I am going to bring my Grandson up knowing the ways of the wind. If I build well I can pass the boat along for someone to do the same.

http://www.seawardadventures.com (http://www.seawardadventures.com/)

[Zaneroni]

Thank you all for your feed back. it only became harder to choose between 2 very good designs. I'm gonna have to flip a coin !
Thanks again.

[Maximus]

Zaneroni,

It's always nice to see someone else from the Twin Cities getting involved with building. I'd give the GIS my vote of the two, however I'm not sure if it would be the most comfortable boat for two teenage boys and their dad, just the boys, sure no problem. There are a lot of designs out there so take plenty of time to decide whats right. I probably spent six months combing every site you can imagine before deciding on mine.

As far as the plywood is concerned. Youngblood Lumber north of downtown has marine fir plywood. The trickier stuff is the Okume. The only place I believe you can find it in MN or WIS anymore is Midwest Boat Appeal Inc in St Boni's. Andy is the owner and a good guy, he stocks Okoume, meranti and one other, all are very nice, okume being the lightest and most expensive. When I was there last he had 4mm, 6mm, 9mm and 12mm of all three.

I think if you're going to go through all the work of building this boat you should do it right and go with the Okoume or meranti. It's not cheap, but it's a beautiful wood that would look good in a natural finish. It's light, easy to work with, cuts and epoxies well.

I can give you Midwest Boat Appeals number if you like, just shoot me a message. Good luck and have fun with the building, I've enjoyed that as much as I do sailing.

Brent

[MiddleAgesMan]

The Goat Island Skiff should be built with okoume, with NO fiberglass except for the 2" tape at the chines. If you use any other 6mm material your GIS will be 50% overweight and will not perform as designed or expected.

[Clinton B Chase]

Let's not get too crazy. Sheathing the bottom in glass would not hurt performance! But planking it in Meranti would indeed make it a more burdensome boat, quite the opposite of what BoatMik intended.

Clint

[callsign222]

A good thread here (http://forum.woodenboat.com/showthread.php?t=111594&highlight=goat+island+skiff).

[James McMullen]

Old fir marine plywood is in no way, shape or form the same animal as the current fir plywood, guys. Stories about the longevity of 40 year old boats are great, but they weren't built from the same stuff that's being sold nowadays.

I built my first rowboat, a Chamberlain Dory Skiff, out of beautiful AB Marine fir in 1989--it even came in a 4x16 sheet already so I didn't have to scarph it. This plywood was made from enormous, old-growth coastal Oregon fir trees. . .

. . .fast forward 21 years later--those trees are GONE! They don't have them to spare for making plywood anymore. The plywood you buy today that is labelled "fir marine" has barely anything in common with the stuff from back when.

How many sheets does it take to build a GIS? Three or four, maybe? I'd be surprised if it cost as much as $100 more total to use the good ply versus using cheap, wrong stuff. Don't be penny wise and pound foolish. You will spend just as much or more time and effort building a crappy boat out of shoddy materials as you will building a decent boat, so why waste your time.

[leavittg]

I agree with all the plywood quality comments, but I just wanted to add that at the two local lumber shops I just checked with here in Portland, OR (Brown Lumber and Mr. Plywood) both said that they could order in 4x10 and 4x12 sheets of plywood. They said that they didn't stock the bigger stuff due to lack of demand. Also, they were a lot more expensive than the 4x8s. Mostly I was concerned about being able to sort through for the best pieces and transportation, so I just went with 4x8 African mahogany marine ply ($45 per sheet).

[Spokaloo]

Roseburg is still producing sheets up to 4x16 by order, so if they are supplied by them it's still a shot. You can also request grading of AB marine with b cores including footballs. I don't know if you can get AA with A cores, but it'd be spendy if you did.

I personally have fallen for building in MDO if you are looking to make a workboat finish. It's available down to 3/8", which is a little heavy for your requested boats, but you could ask them to lay MDO over your 1/4 sheets as well.

E

[Plumbtex]

If you want to sail - GIS, Row - Mollyhawk, Row and sail - GIS.
As to plywood: a couple of days ago I would have agreed with all of the above, that was before I found my indoor stored BS1088 Hydrotek meranti marine ply delaminating with just casual exposure to water ( washing machine leak in the garage) while my cheap, big box store exterior ply lives happily outdoors in all weather with no delam. I've found large voids in Hydrotek, MDO and especially big box exterior ply. I haven't used any okume due to it's price and tendency to rot. When it comes to plywood, I don't know what to believe in anymore.

[James Corduan]

Has any one used Aquatek, and how is it compared to Luan. I live in north Texas and marine ply is hard if not impossible to find here, don't want to pay for some high dollar ply to end up with junk. Sorry if I'm highjacking this thread, I have no personal knowledge of these designs, but have admired GIS from afar for awhile.

[Clinton B Chase]

When it comes to plywood, I don't know what to believe in anymore.

It is very tough...you are not the only one!

I am thinking about how to plank my Deblois Street Dory and wish to find a domestic fir ply that is good enough for at least the garboard. The topside planks will be WRC and bottom plank will be glued up local cedar. Do your homework and go with a company that will really back up their product. This is why I am so intrigued by Bruynzeel. Epifanes stocks it here in Maine. They put out a 2-year guarantee on their panels! That is on top of the BS1088 and Lloyd's ratings.

[David G]

Has any one used Aquatek, and how is it compared to Luan. I live in north Texas and marine ply is hard if not impossible to find here, don't want to pay for some high dollar ply to end up with junk. Sorry if I'm highjacking this thread, I have no personal knowledge of these designs, but have admired GIS from afar for awhile.

I have used both Aquatek and Hydrotek with very good results. Compared to occoume, it's both heavier and a bit more prone to splintering when cut across the grain - but is apparently more rot-resistant.

[David G]

It is very tough...you are not the only one!

I am thinking about how to plank my Deblois Street Dory and wish to find a domestic fir ply that is good enough for at least the garboard. The topside planks will be WRC and bottom plank will be glued up local cedar. Do your homework and go with a company that will really back up their product. This is why I am so intrigued by Bruynzeel. Epifanes stocks it here in Maine. They put out a 2-year guarantee on their panels! That is on top of the BS1088 and Lloyd's ratings.

Clint - there is still some decent AA Marine Grade fir laid up here in the Pacific NW. I've always liked MDO - but my supplier has changed the spec to allow cores of more rot-prone woods... so I'm less inclined to use it these days (though I'm still digesting the ramifications). I haven't used fir in years without adding in a bit of glass in epoxy. As little as 2 oz. glass has proven effective at checking the formation of surface checks.

[Clinton B Chase]

David, Would Edensaw have some of the better grade fir ply?

I'd plan on doing a light sheathing for sure.

[David G]

David, Would Edensaw have some of the better grade fir ply?

I'd plan on doing a light sheathing for sure.

Likely - but I've never bought from them. I have some decent, more local, suppliers.

[Cuyahoga Chuck]

If you want to sail - GIS, Row - Mollyhawk, Row and sail - GIS.
As to plywood: a couple of days ago I would have agreed with all of the above, that was before I found my indoor stored BS1088 Hydrotek meranti marine ply delaminating with just casual exposure to water ( washing machine leak in the garage) while my cheap, big box store exterior ply lives happily outdoors in all weather with no delam. I've found large voids in Hydrotek, MDO and especially big box exterior ply. I haven't used any okume due to it's price and tendency to rot. When it comes to plywood, I don't know what to believe in anymore.


If your BS1088 Hydrotech was marked or even claimed to be so and it delamed from exposure to cold water you should get your money back. The BS1088 requirements stated a sample had to survive 24 continuous hours of boiling.
Even tho' the BS1088 standard is no longer used the list of requirements should still be available on the web.