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Permalink Reply by wade radina on September 27, 2011 at 1:43pm

Please disregard, I found the answer from some 2009 posts, searched under "ribs".

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Permalink Reply by Sandy Pittendrigh on September 28, 2011 at 9:32am

I won't try to answer all parts of your question.

Instead I will point out epoxy on plywood will do more harm than good, if it isn't used in conjunction with fiberglass fabric of some kind. Without the fabric the epoxy will spit and crack.  The cracks will allow moisture to seep in, which will soak into the plywood and stay trapped there, hidden underneath the not-cracked areas.

 

Epoxy makes a good glue for joints. But it is counter-productive to use it for coating plywood....unless you also use glass fabric.  Then it's great stuff.

 

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Permalink Reply by Scott Hepler on September 28, 2011 at 12:13pm

I know I am probably missing something but jason has been building boats a long time with just epoxy on the insides of his boats. He only glasses the outside, then paints the outside and Bristol finish over the epoxy inside. The glass on the outside is for extra protection of the wood so it doesnt get damaged and allow water in the ply. My last two boats were just epoxy inside then varnished. One is just two years old but the other is over eleven. Isn't the name of WEST systems the acronym of Wood Epoxy Saturation Technique?
I would only expect inferior plywood to check. If you use okume or merraniti and epoxy then varnish you don't have to glass.
Scott

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Permalink Reply by Lee E Washburn on September 28, 2011 at 5:13pm

Scott your also right bottom line its all about MAINTANCE & proper storage after use .  Epoxy will not hold up to UV. there fore has to have primer and paint. or varnish  keeping varnish up has keep me employed for years. thanks to the SUN.  

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Permalink Reply by Lee E Washburn on September 28, 2011 at 10:46am

 The  joining surfaces should go  raw. wet on wet. look at how the Tolman skiffs are built. you will find all the answers there/ along with years of KNOW HOW.  Hope you taped off the joining faces. if not grind them with 24 grit. just my 2 cents. I planked boats with Thaokel {spelling }  space age stuff  over 40 years ago triple planked bottoms still alive today the oak ribs on the other hand have gone away and been replaced/ hope your nailing with copper ring nails. Enjoy the build   just saw sandys reply he is right on. I sugest  resornial glue for oak and teak. epoxie have come a long ways in my life time. I think of plywood  yachts and 50 gal barrels on shell epon.

what a night mare  came to love boat building.

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Permalink Reply by wade radina on September 29, 2011 at 9:35am

Thanks for your help. I know which way I'm going with this. Love this site--it's my fill in the blanks answer between my Don Hill plans and Fletcher's book.

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Permalink Reply by Lee E Washburn on September 29, 2011 at 8:21pm

iam new here and plan on Don Hill plans  and fletchers book/ do you have the Gougeon book I still have a first adition and i think there on there 5th. you neever stop learning when it comes to boats.I was raised under the keel of an H28 my dad built after world war II. Ive never left the conection to the sea. nor will i ever.  ENJOY   LEE

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Permalink Reply by Don Hanson on September 30, 2011 at 8:30am

 Do coat the parts before you assemble.  Don't be stingy with the epoxy, sometimes two coats are called for, especially on end grain or porous woods like mahogany or meranti.  5200 or Sika will stick to epoxied wood just fine. I have even done three epoxy coats on some spongy end grain and on western red cedar.

  The trick with epoxy for a finish is to put it onto the material at a proper temperature, both the material and the epoxy need to be quite warm.  I like to roll it on and then go back over it with more while still wet, after the wood shows bubbles as the epoxy goes into the grain.   Then when that first coat dries, on porous woods especially, you will see little popped bubbles or craters on the surface....for me, this indicates I want another coat on there...so I hit the surface with some 80 to 120 paper and roll on another coat, then tip it with a brush..The second time over, it takes much less epoxy, but this is the step that will make a big difference for a clear finish that will be exposed. 

Then again sand the surface...(with experience, you will discover there is a "sweet-spot" during the cure time for epoxy when it is quite easy, "just right"... to sand) Now you can treat the coated wood just like any wood and varnish it.....I do two coats of varnish at least....and use a good quality varnish...If your boat sits in the sun, you will probably need to re-varnish every year.  If you shade it during storage, you might get 3 seasons from a carefully applied finish as described above.

  If you epoxy-coat and varnish the boat after you stick it together,  the joints that have any flex at all, the epoxy will crack there and allow water in.  If water get into the surfaces between the pieces, it will migrate to the fasteners and wick into the holes, eventually causing rot or discoloration.

  Here's another tip:  Always put something on every single threaded fastener before you run it into the hull.  Depending on what the fastener is meant to do...I use different bedding compounds.  For screws and bolts that are in raw wood or that will need to come back out, I use Dolphinite bedding compound.  For most semi-permanent fasteners, I use the same 5200 or Sika or modified epoxy that I am assembling with...just run a bead out on some scrap wood and dip the screw or bolt into it before putting it in the hole.... Note: If you pre-coated the parts you are assembling, you can just wipe the goo off after you stick the parts together. 

  Any fastener will penetrate the surface you have so carefully sealed....And they create a nice hole in the material that begs for water to wick right up the fastener...put something in every hole, that is what I was taught during my apprenticeship....(except on clinker boats...those are supposed to leak until the planking swells and closed the holes)

 

  Don Hanson

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Permalink Reply by wade radina on September 30, 2011 at 11:19am

Wow, thank you for the effort of your reply, I'll follow it to the letter. My boat will live in Kansas and float mostly in Colorado and Wyoming--six floats a year if I'm lucky, and live indoors. I'm trying for functional and beautiful (natural wood), so the clear finish is a must for me. Thanks again.

 

Cheers,

 

Wade 

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