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Here is WHY you use good plywood! **UPDATE on pg 6 **

Posted: Fri Apr 15, 2011 1:38 pm
by gstanfield
I thought I would share my misery with others in the hopes to save someone some trouble on down the line. Around here I have two choices for marine plywood.

#1. I drive 500 miles round trip to buy BS1088 Meranti Hydrotec ply

#2. I pay to have it shipped 2,000 miles from Florida

Neither of which are ideal, but in the future I will be going with one of those two. Here's why....I bought the best exterior plywood I could find locally and still had to drive 70 miles round trip to get to the nearest lumber yard for it. The wood was about $25 a sheet and actually looked reasonably good for what it was. It had very few voids in it and the ones that I found were small. I figured it would work just fine for a FL14 seeing as how it's a displacement boat that will get used mostly for drifting down river or use on the lake with a trolling motor. Well, after 11 months here is what it looks like:
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The ply was coated with three coats of epoxy and thankfully I fully glassed the bottom. The interior oddly enough looks very good, but the outside has these places all over where it's coming apart literally. I'll probably fix them, but I'm half determined to just grab the ol Stihl chainsaw and have a few minutes of fun. I'll probably build a new boat first though and keep using this one until either my new boat is splashed or this one sinks :lol:

Oh well, live and learn. I just wanted to share with others to hopefully answer a few of the "can I use cheap plywood" questions :wink:

Re: Here is WHY you use good plywood!!!

Posted: Fri Apr 15, 2011 1:51 pm
by TomW
I feel for you George! :(

Re: Here is WHY you use good plywood!!!

Posted: Fri Apr 15, 2011 2:58 pm
by Crazy Terry
Thank you George:

Thank you for taking the time to take those pictures and posting them. I almost went with a cheaper alternative ply myself. I am very glad that I listened to the advise that the pros gave me and went with meranti. It is awfully big of you to admit your mistake and to post it for all to see. So that others could be spared this disappointment as well.

The true stature of man can be measured not by his wealth. But by his willingness to admit his faults and mistakes. You are a man of great stature.

Re: Here is WHY you use good plywood!!!

Posted: Fri Apr 15, 2011 3:44 pm
by Spokaloo
George, no biggie man, you've got all the skills needed to fix it. Just tear the bad wood apart, patch it up with a little milled glass and epoxy, lay a little glass if needed, and get her back to work!

No big thing, fix and move ahead!

E

Re: Here is WHY you use good plywood!!!

Posted: Fri Apr 15, 2011 4:19 pm
by gstanfield
For sure Eric, and you're welcome Terry. I didn't post that looking for sympathy or anything like that. i posted it so that people would have a visual as to why they need to go with good plywood.

It's an easy fix, as Eric said. I'm just not certain how much more time I want to invest in this boat. It's a good little boat and I like it for what it is, but I'm building a larger boat for the family and a smaller boat for when it's just me so I'll probably just do a quick fix and use it for now without worries. The registration is good for 3 more years so why not :wink:

Oh, I forgot to mention there's about a hundred spots like that so the fix would be a bit time consuming, but not hard.

Again I just wanted to post it as a reference for future builders who want to go the cheap way. In all honesty the inside looks fine it only split o the outsides where the curve was pulling it apart and a thin layer of glass would have fixed that. I'll probably use cheap wood on some of my future "toy" builds, but never on a serious boat 8)

Re: Here is WHY you use good plywood!!!

Posted: Fri Apr 15, 2011 9:46 pm
by Crazy Terry
[quote="gstanfield"]For sure Eric, and you're welcome Terry. I didn't post that looking for sympathy or anything like that. i posted it so that people would have a visual as to why they need to go with good plywood.

Sorry George.

My intent was not to express sympathy. My intent was and is to express gratitude for your willingness to admit an error in order to save others from the same mistake. Thank you for that.

Re: Here is WHY you use good plywood!!!

Posted: Fri Apr 15, 2011 10:49 pm
by gstanfield
Worry not my friend, I didn't take it that way. I was just wanting to express my reason for posting :wink: You owe me no apology 8)

Re: Here is WHY you use good plywood!!!

Posted: Fri Apr 15, 2011 11:14 pm
by Prarie Dog
Tough break George. That ply was probably made from those windblown trees up there. That last bend was one too many :(

Re: Here is WHY you use good plywood!!!

Posted: Sat Apr 16, 2011 10:50 am
by fishingdan
Thanks for posting this. It is a good example of "checking". People often ask what this is and it is tough to visualize without seeing it. Once people see it, they recognize it immediately.

Best practices based on this example:
- Use a BS1088 stamped ply for your boat even if you have to order it/ship it from elsewhere. There is a premium cost to this, but once one sees and work with these products, they get it. They are worth every penny during the building phase as well as long-term use in the boat. As a % of total boat cost, it really doesn't add that much more to go this route. Meranti is an excellent choice.
- It used to be that one could find decent exterior ply and use it for a smaller boat, but the ply available today locally is usually only suited for home building tasks.
- If you find decent exterior play or go with marine "fir", you need to apply glass cloth to all surfaces. This adds weight and cost, but one will experience checking over time if this step is not taken. A simple 4oz or 6oz cloth applied to the surface will stabilize the surface in most cases and add some puncture resistance to the surface. This cloth is not the structural biaxial used as a specific structural component of these composite boats. A light woven cloth is very easy to apply and is nearly invisible after it cures. The weave is also very easily filled and often fills with a coat of epoxy.

Re: Here is WHY you use good plywood!!!

Posted: Sat Apr 16, 2011 1:00 pm
by Steven
The real fix would be to take all not glassed wood down to epoxy and then add a light fiberglass cloth. I built the Cheap Canoe out of exterior to learn the methods. Its started just like in your picture with a few spots. I sanded down and filled them and repainted. Waste of time. It just goes on and on and on. Now it's a yard toy for the kids. Great bottom that is glassed, but all non glassed areas are chock full of checks. Great post.