new but ambitious

In US it is usually BS1088, meranti is much cheaper usually.

12mm of okoume BS1088 is around $70 per sheet plus delivery. http://www.noahsmarine.com/United_States/Plywoods-us/plywoods-us.html

That was B/B, but I have seen A/B for not much more.

 

Very good point.
I have to check out some more information, maybe I'll finally opt for a new gas-engine (much cheaper), if the marina's here provide gas-fueling.

I do hope I can do better than PAR's estimate of doubling the estimated time, but I do realize it'll take me much more than an experienced builder.
I hope to limit the time excess by proper planning and preparation before starting the construction.
I've got time anyway, since I'll pay next to nothing for storing/protecting.
Any estimations in the number of hours normally needed to actually build a project like this (planning etc. not included)?

 

Thanks for that!
How big are those sheets?
I've read somewhere that some people consider meranti plywood a little better than okoume.
Any experience/opinions about that?

 

No personal experience, but everything I read from 'experts' indicates the only advantage of other plywoods is cheap cost not performance.

BS1088 has no internal voids, all faces are at least 'B' grade - some are 'A' grade. It is WBP glue throughout - will not separate when wet.

The other plys are cheaper, but not better.

http://plywood.boatbuildercentral.com/help.php -- meranti is usually BS 6566, not BS 1088. BS 6566 allows mixed woods, and voids. Okoume seems to be a little lighter and slightly more durable - don't quote me on that, that is memory.

I think on comparisons, you will find the same material in the US to be just slightly more expensive. Usually, 20% to 30%.

The anti-American tax plan.

Sheets are usually, 4'x8'.

 

Thanks El Guero!

 

I have a question about epoxy brands.

Here in Thailand, the common brand is JOTUN.
at the local department store, I was advised Jotun Seal guard.
the funny thing is, I can't find this specific product on their website!
Also, the technical details say "contains epoxy constituent".
Does this mean it is epoxy, or does it mean it contains just a little epoxy?
Can this be used to fiberglass a boat?
Price = $55 for 4 liter

 

You will have to ask locals that question, there is no way to effectively translate technical data ....

You would not believe some of the misses I get in Ukraine. тмин (Tmeen) in Russian is Cumino, gotta have that for my Mexican food. BUT, тмин in Ukrainian is something else, even though it is TRANSLATED as cumin ....

I gotta have my Mexican food! So, I take my spices with me.

 

ok, thanks!

finally found a real plywood dealer in Thailand.
4' x 8' sheets at 62$/sheet, 12mm (1/2")

Cheaper then in the US I think, but I also discovered I'll probably need double the amount I originally anticipated, bringing the plywood cost at about 4.000$!
Although they claim it is made according to BS1088, they also say it's "mixed radish tropical hardwood".
Isn't BS1088 supposed to be made of 1 and the same hardwood???

 

It's very common in that part of the world, to find BS-1088 markings on materials that don't come close to to the actual requirement. In fact in recent years, China and some southeast Asian countries, have flooded the market with plywood marked as Lloyd's certified, but it's surprisingly cheap. When tested it fails, on all areas of interest and isn't even good as siding on a house. Again, more information gathering on your part is required. Research the Lloyd's certification and British standards used. Lastly only purchase from known good suppliers and if a price looks to good to be true, it probably is.

 

Thanks PAR!
I'll keep on searching!

 

PAR, I have a question specifically for you!
I've been checking out the boat designs on your site, and there's something I don't understand. I hope you can help me out here!

While researching on the net, I found following formula to determine max. speed of a boat with planing hull:
Vmax = K x square root of SHP/weight in long tons (displacement) of the boat.
K factor is based on the length of the waterline, and the exact planing shape (soft chine/hard chine (list provided)
I.E.: if a boat with hard chine planing hull has an engine with SHP = 150 HP, a waterline of 25' and a weight (displacement) of 2 long tons, the max. speed of this boat should be
2.9(K) x rootsquare of 150/3 = 2.9 x 7 = 20.3 knots max. speed (more or less).

How than, is it possible that a boat with 4.6 ton displacement and about 20' feet waterline (K=2.75 max) and a 75 HP engine, generates 23 mph (19.9 knots)?
According to the formula I found (www.yanmarhelp.com/o_perf.htm), the max speed of this boat should be approximately 11 knots.

Is this formula wrong, or are there other things to take into consideration?

 

pipergsm, I see you trust blindly on a formula that you found on the Internet, with which you can easily calculate the curve power / speed of a planing hull. I recommend you do not rely much on that formula and you read some articles by authors such as, for example, Daniel Savitsky.
Thera are so many factors involved in determining the maximum or most economical speed of a ship, tan to reduce the solution of the problem to a simple formula with three variables, I think is a big oversimplification.
Surely your internet formula is correct if applied correctly, but nothing more.

 

OK, I understand!
The formula is probably a simplified presentation, so that amateurs (like myself!) can have "some" idea about power/speed correlations.
Too simple to be really accurate.

I hope you'll have patience with me guys!
No doubt I will pose many more questions like that, sorry! (I warned you for my "stupid questions", LOL)

Thanks for the link by the way!

 

If you are really hell-bent on making a plywood cruiser, and you don't want to over-complicate matters or send the bill through the roof, you'd best consider a design that can be sheeted with continuous 4' wide material both topsides and bottom, otherwise you will joining sheets of ply both lengthwise and crosswise like it is going out of fashion. That will also mean the surfaces must be developable, a subject that is covered pretty well on the forum, including recently.

 

pipergsm, you have to ask and seek answers but many times, even with the answers that we give, you need to know how to interpret them and to know on what terms are applicable and in which fields are not.