# Type of plywood to use



## johnfaris3

I have been reading several boat building and boat related forums for over a year now and learned an incredible amount.  (Thanks to all that have contributed).  

My question is this...what types of plywood are forum members using for their builds?

I have seen advice ranging from use only the best like Okume, BS1088  (b/c it will end up saving you epoxy and time) all the way to the "mullet boat" option which as near as I can tell is some 1/2" external ply, glue, and porch paint.

I am about to start my first build and have no intention on this being the boat I will pass down for generations.  I want to fish and get on the water for a reasonable cost.  I have already decided on using epoxy, but I am still undecided on the type of wood.  I have seen several types of ply from 1/4" to 1/2" that look good (virtually no voids) at the local big box stores.  These are usually labeled things like "premium underlay" and I have seen birch ply that looks very nice too.

Your thoughts?


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## Boatdesigner

The bare minimum to me would be some type of high quality EXTERIOR ply. If it isn't marked exterior, then the glue is not waterproof and will delaminate in water. I would recommend Meranti marine grade ply for the hull and use a less expensive exterior ply for the deck to save some money. If you use a good grade of wood, you may be able to get away with just coating it with epoxy and painting with exterior house paint.

Okoume is lighter and more expensive than Meranti, but isn't as rot resistant. Hope this helps!


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## DuckNut

Boatdesigner nailed it but I would also add depending on your build.

If your build has curves you have to be careful of fir.


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## KnotHome

Depends on your final design. To just get on the water, I'd build a mullet skiff with a 3/8 bottom, 1/2 sides and 3/4 transom all on exterior ply and use good paint.


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## Brett

The bottom is 1/2" exterior grade furniture plywood
sides and bulkheads are 1/4" exterior luan
transom is 3/4" exterior pine plywood.
All from Home Depot.
All encapsulated in epoxy and 6 oz tooling glass.


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## firecat1981

I built mine using moisture resistant 1/4" luan for the hull and 1/2" doubled for the transom. 3/8" for everything else. All covered in epoxy and 6oz cloth. It took a hit from an SUV doing 35mph and still floated!

If I were building a 20ft+ boat for crossing big water I might consider using marine ply, but for a little skiff I just don't think it's worth it. I'm about to start on my next boat build and will most likely use 1/4 luan, or 1/4 ply again.


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## riptide

Okume ply hands down , if your gonna build your boat , the time you will spend will far out weigh the material cost , do it right the first time. marine grade plywood holds up better period. do a test ,ask for a mg plywood off cut ,and a lluan off cut, toss it in a 5 gallon bucket with water for a week or 2 and see for yourself. here in nc i can get 1/2 lloyds of london 1088 for 60$ a sheet you might have to look for it , but a boatbuilder that builds a cold molded boat will have tons of it


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## firecat1981

> do a test ,ask for a mg plywood off cut ,and a lluan off cut, toss it in a 5 gallon bucket with water for a week or 2 and see for yourself


If you have a water intrusion that bad then either you didn't do the job right in the first place, or you don't take care of your boat the way you should. 

The problem with marine ply is the price, well ok lets be real thats the problem with anything that has marine in the name. For a microskiff you really need to do a cost benefit analysis with your materials, if you go full out on marine ply then by the time you finish it may have been more expensive then just buying a new boat like the native suv, or inshore 16. The water proof glue thing is misleading, as most plywoods today use water resistant glue similar to marine ply. The big difference comes in the voids, however many exterior grade plys have little to no voids these days. But really if you are fishing protected waters and flats and use epoxy, and you should be using epoxy, then you will have no trouble if you build it right. 

Alot of this also depends on what you will be building, so what are your design plans?


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## copperhead

There is a reason 1088 is rated like it is. Given the number of hours you spend on labor and epoxy, the extra cost of 1088 is actually a small percentage. There are more plies in 1088 than any exterior grade. It bends more fair decreasing finishing costs and time. If you like fairing and sanding, get the cheap stuff.

You really have to decide the ultimate use of your skiff. I've built a bunch of prototypes with big-box ply, but they were throw away protos. But even for throw away plugs for a final design, I get 6566 which is like 1088 without the Lloyds cert.

Just my opinion....


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## WhiteDog70810

What's more important to you, the budget or the boat? You already said you aren't out to create an heirloom, so I think your answer is on the table. However, you've got to have faith in this thing once you make it. If you are comfy with exterior luan, go with it. If you would feel better with marine, you should probably pay for it. Brett and firecat are happy with their results, but your gut won't lie to you.

Duckworks has a free "Duckskiff" plan at the bottom of the Plans page. Its curves are very simple and it will slap together quick/fast/in-a-hurry with luan exterior. It might be a good fit for your needs, ie simple, functional, economical, not a museum piece, but also not an ugly floating box.

Nate


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## DuckNut

Listen to copperhead. Also on the glue part. I call BS on the whole water resistant/exterior thing as being acceptable.

Take a piece and boil it for 10 minutes- if it comes apart the wood is crap.


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## B.Lee

Brett, Firecat, adn myself have all recently built our boats using exterior ply and luan. The way it's built factors greatly in here as well.

None of us (or most others) leave their boats in the water, and boiling the wood is a bit extreme for a test of the glue, but I get where you're going with it.

We didn't build wood boats, we built composite boats, epoxy and glass over a wood core. No piece of wood should ever be exposed to water with the exception of some sort of damage being done that would expose the core. 

First build, a small skiff? Luan's cool with me. I found flaws in mine, but nothing that would stop me from using it again, it's jsut what I paid for, cheap, smooth ply.

Mine's finsihed to a "workboat" level, no fairing, just sanded, and painted with exterior latex. The whole boat didn't cost me $900, labor not included, because it's a hobby, not a job. I've got 1.5 gallons of epoxy left over too, so we can cut that cost number down even more.

johnnemo, I'd personally recommend luan. As your first build you'll learn a ton, make mistakes, and end up with a boat that'll work. You'll also have a wealth of knowledge to apply to your next build, and I'd save the expensive ply for something you may build later when you REALLY know what you're doing!


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## Bob

I know of a couple of builders that decided to save money on their plywood. Once the boats were finished & they turned out better than they expected, one of their regrets was using cheaper plywood instead of okoume. Fortunately I didn't make that same mistake.


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## The_Skiff_Shop

If you have any interest in this boat you could have the best of both worlds. 

http://www.bateau.com/proddetail.php?prod=XF20

If your interested, contact me @ [email protected]


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## MATT

There is form member that (I will not use his name) rebuilt a Mitchell Skiff and used stollen signs from a constuction site or flea market....not sure, the point here is if the wood is coated the correct way it will work......but I also belive that you get what you pay for. When I start my build I will use the best. My time is worth the best.....


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## Un-shore

> I know of a couple of builders that decided to save money on their plywood.  Once the boats were finished & they turned out better than they expected, one of their regrets was using cheaper plywood instead of okoume.  Fortunately I didn't make that same mistake.


Did something happen that made them regret using cheaper plywood?


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## Brett

Coming up on 2 years of inshore use,
crunching oysters and sliding over sand bars.
No leaks, no squeaks, no rot.
Cheap plywood for a cheap hull.
If I was going to be using it on deep open water
there'd be okume everywhere.


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## MATT

Like your new motor Brett....


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## deerfly

> Like your new motor Brett....


yeah, changes the whole look from a dainty put-put to racing skiff.


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## Un-shore

I had to look twice, that little wave made it look it has a step hull. I thought you got bored or something! ;D


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## Frank_Sebastian

The moisture resistant underlayment just won't last. There is one that will. It can be found here.

http://www.morelandcompany.com/ultraply.htm

I have built a number of small sailboats with the Ultra-ply. I still have one that I built in 1993. It is fine today and in my back yard.

Go cheap on the first boat, but not so cheap as to use plywood from the big box store. If you read the labeling it will say something like "water resistant while under construction" or exposure rated for 30 days.

Fir and pine plywood will "check" or get a bunch of small surface cracks that lets in moisture and water. Try to avoid it. I use only meranti with BS1088 going into the hull and BS6566 for seats, decks and soles. 

I don't build fancy boats, but I do build good boats. If you build a good design with acceptable materials and build it right, it will last many times longer and be more enjoyable to use than one thrown together on a whim, even with a workboat finish.

Best regards,
Frank_S


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## Frank_Sebastian

Sorry! I just realized I forgot to specify the XL. It is heavier and I prefer it for anything with power.

http://www.morelandcompany.com/ultraplyXL.htm

Also read the how tos here.

http://boatbuildercentral.com/howto.php

Good luck and best regards,
Frank_S


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## firecat1981

heres a link to a decent explanation that lead me to choose the luan that I did. 

http://www.oneoceankayaks.com/stitchglue/plyshophtm/plytype1.htm


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## riptide

I do not know any reputable boat builder in nc that doesent use marine grade ply


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## Brett

We're a disreputable bunch here in Florida... 

Like this home built kayak I saw at the ramp this morning.
Constructed from 1/8 inch birch furniture grade plywood.
Rigged for fishing the oyster marsh in NE Florida.




























The owner had reason to be proud of his work.


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## FlatCat

I chose fir marine ply for my project...basically a "tweener", less than Okume, but has a true marine adhesive.
Quality plywood in Sanford carries much better/less $ inventory than the depot, i'm pretty sure they will sell in small retail lots.
Good info on the kyak site link.


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## firecat1981

Nice find Brett, I guess woody's are popular in your neck of the woods ;D



> I do not know any reputable boat builder in nc that doesent use marine grade ply


Yes we must be scum here in Florida then, lol. If you are building boats to sell then a company really has to use certain materials or else they wouldn't have customers, warranties, or insurance. We are building our boats here not for business purposes, but for our own personal use. 
On another note I don't know of any reputable builder who uses any plywood in a skiff these days!


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## Bob

> I know of a couple of builders that decided to save money on their plywood.  Once the boats were finished & they turned out better than they expected, one of their regrets was using cheaper plywood instead of okoume.  Fortunately I didn't make that same mistake.
> 
> 
> 
> Did something happen that made them regret using cheaper plywood?
Click to expand...

yeah - Weight. Okoume is 20+% lighter than other plywoods. People worry about the weight of the outboards, draft depth, & on & on. Why not start with the hull and keep it as light as possible so outboad selection & other add-ons won't be that big of an issue. 

Also, after all was said & done the extra expense for the best plywood was a small percentage of the total build, so why not start out with the lightest and easiest to work with?


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## firecat1981

I didn't know it is lighter, but outboard weight is a major concern because it is all at the extreme end which makes the rear draft more, but if the weight is distrubuted through out the whole boat it won't effect much. I can see however on a larger boat or yatch 20% would be huge.


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## B.Lee

20% on a 5k lb hull is significant, and the forces applied to a hull of that size fully warrant the use of the best quality materials, we would all agree on that.

20% of my sub-300lb hull is minimal. That 60lbs spread evenly over the hull shouldn't increase the draft any signiicant amount.

Outboard weight is worth the thought because it's all hanging off the back, and a bit of leverage there amplifies whatever weight is already there.

Folks also bicker about weight of all kinds, but they themselves tip the scales at a hefty number of lbs, I always found that interesting. When I rode motocross, there were guys that would obsess over saving 3 lbs with a titanium or carbon fiber exhaust, but their fat butts were 220lbs dry. Skip the biscuits and gravy if a few lbs is such a big concern!

For the record, I'm 210+, but I don't care about a few pounds here and there either...


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## Brett

> Okoume is 20+% lighter than other marine plywoods


fixed it for you... 

1/4 inch okoume weighs the same as water resistant 1/4 inch luan.


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## firecat1981

Ah that makes a little more sense now, I was scratching my head trying to figure out how anything could really be that much lighter then luan.


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## B.Lee

I was too, but having never picked up a piece of 1/4" okume, I was giving the benefit of the doubt there. Luan is lightweight stuff!


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## Conch_and_Cracker

Not only issues with glue it would be with the voids in the lesser quality of plywood. Even at slow speeds the reverberations and pressures the wood takes it will delaminate over time. Just hope it's not when you are motoring down the river. Really spend the money and buy quality materials including the wood you use, not just he ply wood. The more plies you have in the plywood the stronger it will be. If you use epoxy make sure you cover all 6 sides or don't waste your time or money


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## Un-shore

With the type of bulids I see brett, fc, B. lee and similar is that the wood is a small part of the composite equation once you glass and epoxy it.


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## firecat1981

> With the type of bulids I see brett, fc, B. lee and similar is that the wood is a small part of the composite equation once you glass and epoxy it.


That is true, When I built my hull I didn't use the wood for structure, just form, the strength comes from the epoxy and glass layers. The Luan did add some strength, but not nearly as much as the glass.


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## Brett

The major advantage to using marine plywood
is eliminating the need to fiberglass anything but the joints
above the water line. Still have to use glass below the waterline.
Saves a small fortune in fiberglass and epoxy.
What I saved by using cheap plywood, I spent later on more glass and epoxy,
in order to make up for the deficiencies in the wood used.
You'll pay, one way or another!


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## riptide

http://www.clcboats.com/shoptips/stitch_glue/lauan_plywood.html


http://www.duckworksmagazine.com/08/howto/plytest/index.htm


http://www.oneoceankayaks.com/stitchglue/plyshophtm/plytype1.htm                                                

I can speak from experince I am a yacht joiner by trade , in my opnion i will never use any thing else other than a marine grade ply. read some of the links and it will give you some direction , BUT if you want to use other plys it is your boat ,and i understand building the boat the way you want . thats why you are building it right .Here are some pics of rotten areas being replaced with marine grade ply


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## riptide




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## riptide




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## riptide




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## Swamp

Sharp looking work Karl.  You can work on my boats anytime, I'll supply the beer!   How old was the wood being replaced?  I'm getting ready to tear into a boat with wood rot that was probably built in the late 70's to mid 80's.  What techniques are you using?  Raw wood and then paint? Sealed epoxy? Sealed polyester resin? Glassed on one or both sides?


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## riptide

I usually use what is exzisting on the boat , if its polyester i repair it with polyester , and if it is epoxy i repair it with epoxy . I like to resin coat the ply on both sides and let it dry ,before it goes in the boat or before it gets glassed


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## Swamp

Replacing like with like makes sense. I expect you get fewer epoxy fixes compared to poly. Have you noticed a difference in plywood generations as the glue technology has changed? I of course do not know the particulars of my hull, but I see a water line on the hull that makes it looks like the stern of the boat was partially submerged for a while. The water damage is also worse in the back of the boat. Since the boat is made with polyester, I expect even the best of plywood would have taken damage. I just wonder how the modern plywoods compare to the older ones. BTW I DO plan to replace everything below the floor with marine grade ply and it will be completely sealed.


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## oysterbreath

> there were guys that would obsess over saving 3 lbs with a titanium or carbon fiber exhaust, but their fat butts were 220lbs dry.  Skip the biscuits and gravy if a few lbs is such a big concern!


Man, those words ring SOOOOO true. I used to ride road bikes and knew a few people who were the same way.

Karl, thanks for the pictures. Do you do much cold-mold work?

I think using cheap ply on these small boats is much different than on the larger ones. For one, on these smaller skiffs each side of every piece of ply gets glass and epoxy where-as the boat you have in the picture has one side exposed to a void area which is itself a possible water intrusion area due to the rod holder penetrations.


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## firecat1981

> The major advantage to using marine plywood
> is eliminating the need to fiberglass anything but the joints
> above the water line. Still have to use glass below the waterline.
> Saves a small fortune in fiberglass and epoxy.
> What I saved by using cheap plywood, I spent later on more glass and epoxy,
> in order to make up for the deficiencies in the wood used.


So Brett are you saying you wouldn't glass the whole boat if you used marine ply. No matter what material I use, wood, ply, foam.....I still would coat all sides for peace of mind. 

Karl thats some nice work, and I've always said that if my boat stayed in the water or was over a certain size I would use marine ply. Some of those pictures look like they weren't even fiberglassed, were some just coated?


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## Brett

FC, You got it.
On the Slipper I overbuilt to compensate for the low grade plywood.
With 1/4" okoume, I would only have 6" glass taped the seams/glue joints, inside and out,
and covered the exterior bottom with full width fabric.
The interior and hull above the waterline would have been epoxy sealed and gloss coated.
I would have saved more than $500 in materials.
I grew up with plywood over frame hulls, no glass/epoxy at all.
Never had a problem that couldn't be solved using basic carpentry skills.
The good old days of bedding compound and bronze screws.


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## riptide

I use to do alot more cold molded work , not so much in the past few years , I now work for myself and dont take on more than i can handle.

i do not have a pic of the glasswork , usually i coat the wood then glass it , in some of the pics i coated the wood , and came back the next day to glass it . Being outside and dealing with rain and dew I found that if i do that it can rain and i can still glass the boat the next morning.....Sometimes i cant finish what i started in 1 day so it helps me stay productive the next , so i dont have to wait for the ply to dry


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## firecat1981

I don't know Brett, you say over built, I say quality built. I did the math on my project and even if I just coated the decks, compartments and floor I still wouldn't have saved any money and I would have needed thicker material to get the same rigidity I got with the ply/glass. 
There were a few areas on my boat that were just epoxy coated and held up fine, but I am going to put a layer of glass on everything this go around.


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## Erik

firecat1981 said:


> I built mine using moisture resistant 1/4" luan for the hull and 1/2" doubled for the transom. 3/8" for everything else. All covered in epoxy and 6oz cloth. It took a hit from an SUV doing 35mph and still floated!
> 
> If I were building a 20ft+ boat for crossing big water I might consider using marine ply, but for a little skiff I just don't think it's worth it. I'm about to start on my next boat build and will most likely use 1/4 luan, or 1/4 ply again.


Hello firecat1981!
My name is Erik, it's good to meet you here! i was wondering if you still have any of the blueprints/drfting of your "grassSlipper", I'd love to build one! If you do have them, would you be willing to let me use them to build my own, please? Thank you for your time and allowing me to bother you! Happy belated New Years! and Good Fishing!


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## firecat1981

Erik said:


> Hello firecat1981!
> My name is Erik, it's good to meet you here! i was wondering if you still have any of the blueprints/drfting of your "grassSlipper", I'd love to build one! If you do have them, would you be willing to let me use them to build my own, please? Thank you for your time and allowing me to bother you! Happy belated New Years! and Good Fishing!


Good day Erik, this is an old thread. The grass slipper is Bretts, and it' still in use. My boat, the TGIF (thank god it floats) met it's demise by the hands of an SUV at around 35mph. That was 2 boats ago now and I'm working on another one. I don't have any drafts of it sorry, but it's easy enough to make up as you go along. I started with 1/4 scale models.


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## Erik

Thank You firecat!
Did you start it as a stich-n-glue or did you do ply-on-frame? For me, my only concern would be how to draw the lines of the sides to get that nice long flat bottom and then that easy upward smooth curve! i guess I just have to try different drawing and work them up until I get it right! Man Thank You again for the heads up on this, When I saw Bretts and Yours, I was like damn! Thats just perfect! wish me luck and if you have any bits of info. that you remember, please throw them my way! Good Fishing to you!
Erik G.
NJ


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## firecat1981

The proud bow is just the natural twist the plywood wants to take when following the bottom.

The best I can do is direct you to my build thread.
https://www.microskiff.com/threads/and-it-all-begins.16266/

This is my second, much improved skiff here.
https://www.microskiff.com/threads/building-the-plytanic.16663/


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## seapro17sv

firecat1981 said:


> The proud bow is just the natural twist the plywood wants to take when following the bottom.
> 
> The best I can do is direct you to my build thread.
> https://www.microskiff.com/threads/and-it-all-begins.16266/
> 
> This is my second, much improved skiff here.
> https://www.microskiff.com/threads/building-the-plytanic.16663/


Take a look at all the plans on the Bateau sight, and if you choose to build one of their boats you'll get all the support you need on the Bateau forum.


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## Erik

firecat1981 said:


> The proud bow is just the natural twist the plywood wants to take when following the bottom.
> 
> The best I can do is direct you to my build thread.
> https://www.microskiff.com/threads/and-it-all-begins.16266/
> 
> This is my second, much improved skiff here.
> https://www.microskiff.com/threads/building-the-plytanic.16663/


Thank You fiecat! You’ve just made me a dangerous man with a clearer vision! Beautiful boat man!


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## Erik

seapro17sv said:


> Take a look at all the plans on the Bateau sight, and if you choose to build one of their boats you'll get all the support you need on the Bateau forum.


Thanks seapro17sv!
I’ve looked at bateau and spira international too, I’d just like to built it bottom from my own ideas. I think I’ve learned enough to be dangerous! LOL


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## Erik

This is my first stitch-n-glue flat bottom skiff model i’ve Built. I’ve since epoxied and filleted the chime line, bow and transom in place. I figure if I can do it on a small scale model, why not full size! Thank You Brett and firecat1981 and everyone else! I’m going to name her “dirty jersey”


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