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Permalink Reply by chris towles on September 12, 2012 at 3:13pm

Do a search there is tons of info. Pull the chime battens first as these are probably redy to be replaced anyhow. Sand and fix any old screw holes with epoxy..check for any rot that needs to be repaired...then glass the bottom edge to edge mixing the graphite w the flow coats. You want about 20oz of glass..few different ways to get there...3x 6 oz layers, 2x 10oz layers, or going with the 17oz bias which soaks up a ton of resin but is bomber cloth. The bias cloth is arguable stronger than regular glass cloth because it can take stress better on more axis then a regular cloth could, but if you did a few layers and layed One down straight and the next layer at a 45 degree angle it kind of accomplishes the same thing. Once you are done trim the green glass atthe edges or wait till it kicks and hit it with the razor blade first orbital sander second to get the edge tight, then replace the battens with stainless screws and bed them with marine caulk (I like sikaflex 291 personally). I like to putty the screw holes on my batten to keep water out too. Metal strips are key for taking a lot of damage and keeping it from destroying your battens. I put aluminum strips on my boat just last month and in One month they are totally chewed in like 4 places, but my batten is not....means they are doing their job well. Stainless steel half round is supposed to be the best though...but I found my strips at the hardware store for $11 so they were cheap and effective

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Permalink Reply by tungsten on September 12, 2012 at 3:13pm

not sure about the screw holes,but 3 layers of say 6oz glass will weigh more then 1 layer of 18oz,plus its more work.from what i've read most go with one layer of 21oz, this is triaxle glass so theres 3 layers/strands of 7oz glass 0-45-45 the 0 goes the long way on a roll.this also depends on how much the bottom gets hit and how thick your bottom is.say if your bottom is 5/8,then its plenty strong and all you need is abrasion protection.so maybe some S glass or xynole.but if your bottom is 3/8 then you need something to stiffen like the 21oz triaxle,then maybe some extra for the abrasion.

 

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Permalink Reply by Randy Dersham on September 12, 2012 at 4:55pm

We use 20oz triaxel.  This takes care of the stiffness in three directions and has worked out very well. 

Drill out any soft wood from the UHMW screw holes and fill with fillet.  It the holes are large then plug with a dowel and trim/sand when dry.

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Permalink Reply by Duane Doran on September 16, 2012 at 5:37pm

You might look into a polymer bottom coating when you have the bottom repaired. There are a few new products out there that are amazingly strong and also provide complete waterproofing of the bottom. They are also a more logical solution than UHMW as they do not require penetration of your hull. Some people are vacuum bagging thin sheets of UHMW onto the hull but have started to hear some horror stories of the product delaminating in use and nearly sinking boats. The stuff is very hard but the downside is its highly unstable properties when subjected to temperature change. It will expand exponentially when compared to the hull material and epoxy used for adhesion. In other words picture a 90 degree day headed to the Deschutes and dropping the boat in 48 degree water. The expansion from the daily heat followed by rapid colling will tear it apart.

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Permalink Reply by Randy Dersham on September 16, 2012 at 6:19pm

Hello Duane, 

I've answered your other request.  The problem with any wooden boat and fiberglass cloth or a polymer coating is that the wood is the weakest part of the process.  After years the fiberglass or coating seems to delaminate from the wood. In reality it is the top surface of the wood that is delaminating from the wood. 

I have a 16 year old boat that has a polymer coating on the inside bottom of the boat.  The sides were also fiberglasses. I've left it outside for the last four years to see what will happen. (I know, I know-it's bad juju to be a boat owned by a boat builder)  I could power wash that interior bottom today and it will look like new.  However, is not water proof.  The boat is able to leak from the outside chines and come up through the chine leak and into the boat from under the coating.  

I'm not saying that polymer isnt a good idea.  I am saying that what ever method a wooden boat builder uses they need to maintain their wood or the coating that they use become traps for water.

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Permalink Reply by Duane Doran on September 17, 2012 at 9:34am

Randy,

 

From our perspective you have two bviousos areas of concern. The outside bottom which is always wet when in use and the interior floor which is wefrequentlyly. The interior however is the larger problem as water will lay in areas for extended periods of time while the bottom water will always run off. We therefore believe a quality polymer coating on the bottom that wraps the chines solves any issue with the bottom. We alsrecommendnd coating the inside bottom area and any attached and adjacent framing members. Most times this will be under or behind some type of raised wood flooring so it won'totallyly interfere with the boataestheticscs. You have now encapsulated the problem areas and if done correctly will provide years of protection from rot.

Please a few examples below:

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Permalink Reply by Randy Dersham on September 17, 2012 at 5:22pm

Beautiful work.  

I'm a big believer in encapsulation. I also like to encapsulate with Bristol which I know will last a much shorter time than polymer.  So I agree with you. 

What I was trying to say was that in my application I coated the inside bottom and about half way up the chine log.  The water that was leaking into the boat was coming from the seam along the chine outside the boat.  I was originally worried that I could trap water from outside the boat into the bottom plywood and I wouldn't be able to see it on the inside.  The truth is that in that application the typical chine leak found a way to separate the bond between the inside bottom and the wood and come up under the polymer on the inside. The polymer has held its shape and it can look like new when washed but it is not water tight. 

Water finds a way.  That was my only point.  I have no doubt that a polymer encapsulated boat is going to last a very long time. 

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Permalink Reply by AJ DeRosa on September 17, 2012 at 6:18pm

 

 

Duane,

I think that many of the regular posters to this forum are interested in new ways to solve old problems and your product could be one of them.  However I am sure that the old guard, like me, will bristle at the thought of using these untried techniques on a tradition frame built boat.  If this is indeed a panacia it could be a good idea but we have been through this before with ideas like truckbed liner.  Could be a great product for stitch and glue builders who encapsulate all wood in glass and epoxy but the beauty of the traditional framed boat is lost when covered in googumpucky (this is a technical term, thanks DH).  Oiled interiors and well bedded chine caps have stood the test of time and allow for easy replacement of sacraficial pieces like chine caps.  Oiled interiors will  "breath" and are easily maintained.  I have a 1952 Hindmann and a 1967 Ostrem that are "pickled" in oil and in remarkable shape and are being used, not just sitting in the garage looking pretty.

I mean no offense but need to carry the banner of tradition. 

 

I hope that some folks will step up and try these new products and then let us know at 10, 20. 30, 40, 50 years down the line if they work as well as good materials, craftmanship and  well maintained  oil and marine paint on taditional frame built driftboats.  Don't know if they were building fiberglass, aluminum or stitch and glue in those days but good old wood has proven itself over time.

 

Just some food for thought. 

 

AJ

 

 

 

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Permalink Reply by Duane Doran on September 17, 2012 at 9:06pm

AJ,

You are correct in that there is not a history that spans 30-40 to reflect on but our product has been tested to the max and the current biggest user is the U.S. Navy so I am pretty confident in its staying power. That said it does mix the beauty of wood with high technology and some would say that's a sacrilege. I say it's progress.

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Permalink Reply by Bob bryan on October 20, 2012 at 10:16am

I did the same to my tatman and application was pretty easy however I wish I had not and just kept the uhmw shoe. While you do have the issues with the bolts wearing the holes open in the bottom epoxy with wood flour or glass fibers can fix the problem when  it crops up. The uhmw shoe is sooooo much better for getting down the river. I used to guide and believe me without the uhmw shoe it would have been pretty tough sometimes pushing that boat with two big clients over a skinny section. I find the epoxy/graphite bottom is considerably harder to slide over the rocks with just me in the boat than a full boat of big fat guys was with the shoe...just my two cents. I am planning to put a shoe back on mine

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Permalink Reply by Duane Doran on October 20, 2012 at 11:58am

UHMW is certainly the slickest surface on the planet but the application methods just don't make me comfortable. Just heard of a guy who had the front half on the shoe come loose while drifting a very tricky river. It turned his drift boat into a diving plug and damn near sank it. Also hearing lots of stories of failure with the guys who are vacuuming bagging thin layers on aluminum boats. My experience tells me a high-end slippery polymer is still the best bet. Almost as slick as UHMW, equivalent tensile strength, easy to patch small areas, and no risk of sinking my boat if the adhesion method fails.

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