A Question For Norm, Dave Fleming And Others

[Memphis Mike]

Guess What? Douglas Fir Marine Grade Plywood!!!!!!!!!!!!! :D

As you know I'm building Bolger's Windsprint.
I was finally able to get back to the project today after several weeks of mostly bad weather
in Mempho.

I'm in the process of fairing up the sides
in order to be glassed before the outside
chines are installed. The chines have to be
in place before the bottom is secured.

I've used fiberglass reinforced putty {Bondo}
to fill in the cracks and nail holes where
the butt straps exist. As you may guess, this
has included a bit of sanding.

I plan to use 6oz. cloth and polyester resin
to glass this boat with.

I see what you mean Dave by the wavy texture
the sanding has givin these areas. The softer
wood sands while the harder wood does not.

My question: Should I use some type of
fairing compound on this areas before glassing
or will the glass be enough to smooth things
out? If a fairing compound is your suggestion
then what brand and type?

[capt jake]

Well, I am not one of the ones mentioned, but; I had the same delema on the Weekender I am building. I coated the whole area with a mildly thickened epoxy (silica). This gave a uniform 'hardness' to sand on. Then more thickened (microballoons this time), etc.

I felt that there was a need to get the surface somewhat 'fair' prior to the cloth. Final fairing was obviousely done after the glass.

[Donn]

What happened to pics of this project? Are you forgetting the rules?

[stan v]

MM, polyester resin, and not epoxy? Why? Say anything but cost.

[WFK]

Why polyester resin, or for that matter, why bondo? It sands horrible! I'd re-consider and use epoxy as well as epoxy fillers. As far as wavyness in the fir plywood. Time to pull out the flat sanding board. What I use is 3m brand stik-it sandpaper.
Take some contact cement and double up some formica,....cut this into different widths and lengths for sanding boards. It works excellent,....flexable enough for curves but will still take off the high spots

[Memphis Mike]

http://www.imagestation.com/picture/sraid31/p18e0d543b184782fe8a3419df3293741/fd4c8001.jpg

I thought you had seen this Donn. It's the
most current pic I have.

[Memphis Mike]

http://www.imagestation.com/picture/sraid31/p188254c3b95045cc5cf985062fae4c3e/fd4c8000.jpg

Heres another shot. Stan, I want to use
polyester resin cuz this is just a little
cheap sailboat. Besides I like the smell.

[Memphis Mike]

Originally posted by Dave Fleming:
Bondo is or was considered a no-no for woodenboat work but with all the googe you are putting into the project probably no big deal.
Yes, I reckon you are going to have to do some fairing on the hull but what to use? You will have to get one of the folks who use those methods to reply as to the most favoured materials.Dave, yes... I'm using products that were
commonly used in earlier years. I learned
a lot about plywood construction from
my father and it hasn't failed yet... if not
neglected.

[stan v]

Accept this as a strong suggestion, and nothing more. At least use epoxy to tape the seams MM, epoxy is far superior in sticking to wood. You will go from a cheap boat, to one you can use for years.

[Memphis Mike]

Stan, the Diablo you see in the background
was done in Polyester also. It will be in it's
third year of operation this coming summer.

All of the inquiries I've made concerning
the use of polyester resin vs. the use of
epoxy suggest that neither is more durable
than the other.

The epoxy is more easily applied than the
polyester. You get the same finish with
less work.

I may at some point and time use epoxy but
right now I kind of like to do it the way
the old timers did.

[Memphis Mike]

Stan, all BC Yellow Ex. Pine, Polyester
Resin and Stainless Steel. This boat will
be around a long time after I'm gone. It's
tuff.

http://www.imagestation.com/picture/sraid30/p1258a20fd8ddbf75105d2699cd389aed/fd541952.jpg

[stan v]

Good job on the boat MM. As to the longevity of epoxy/polyester, there may be no difference. It's the difference in adhesiveness with wood. However, you don't go offshore and pound, so for the lakes, rivers....

[imported_Conrad]

Well, I'll be in the minority here, but on the other hand I've built a number or small boats, they've all held together, and some have been finished to a level that makes them look like the hood of your car-.......'cause that's what I know how to do.

I think the polyester is fine, especially for new construction that has been kept dry, and is done properly. Be sure to put on a prime coat of reduced resin before adding the cloth. Aside from rough filling the screw holes and major misses, there's no point in trying to fair the plywood until it has been glassed. By putting all of your fairing material on top of the glass, you give the glass a consistent surface to stick to, and get to do all your sanding/fairing on a surface (the glass and above) that has a roughly equivilent hardness. Only a fool tries to fair epoxy on rotary cut fir, long board or not- it just won't work.

Once the hull is glassed, you can use bondo for fairing with great results. Bondo ( really polyester based filler) comes in a wide variety of flavors, however, and you want to buy a grade that is designed more for finishing than bulking out. This will have a higher percentage of fillers, more finely ground and of uniform size, typically smoother to spread and softer to sand. You can additionally thin it with a bit of extra resin, then apply with the largest sheet-rock knife the surface will allow. The twelve inch is my preference- additionally, test for a brand of knife that has the softest/most flexible edge, not the super stiff version. When putting the material on, use long, complete strokes, and don't lift the tool until you get to an edge. Neatness counts, as any extra material just means more sanding.

Some may complain that bondo doesn't belong on a boat, but I have to disagree. It is entirely appropriate for small craft, or any surface that is not continuosly immersed- the easiest, most cost effective solution, and long lived if used properly. There's much more to say, based on 30+ years of success, but you've got enough to do for now! :D

Are you going to put a used wind surfer rig on that baby, or something more traditional?

[NormMessinger]

Not much of the advice you've gotten so far, except for Stan's match my preconcieved misconceptions or my bias again the materials you've chosen so there ya go. What ever works.

--Norm

[ 12-15-2002, 08:17 PM: Message edited by: NormMessinger ]

[stan v]

Interesting Conrad S. In your opinion is there any benefit to epoxy? Everything I've researched gives the nod to epoxy for encapsulating, bonding, fairing, and lay up. Waterproofness is an added bonus. Strength as well. Especially for bonding wood. In fact, cost is the only negative between the two, and that could be argued with what is gained with peace of mind. Maybe this is the question: How much stronger an adhesive is epoxy vs polyester with wood?

[Wild Dingo]

Isnt there a weenie teenie problem with poly delaminating?... seem to member that is why most here are/were against using the stuff and recommend epoxy... aside from the price of course

Well answered Dave... gawd your getttin polite in your dotage mate!! :D

Take it easy
Shane

[imported_Conrad]

No doubt about it, epoxy is a superior adhesive, especially for those examples where you are talking about wood that is continuously immersed. But there is a difference between adequate and superior, and in a situation where the boat is unlikely to ever be in the water long enough to really saturate adequate is spelled p-o-l-y-e-s-t-e-r. In reality, neither epoxy (except for the highest grades with metal fillers) or polyester are truly waterproof.

Epoxy has earned its favor and reputation through its ability to compensate for poor workmanship and improper application. Here in the NW there are hundreds of Tollycraft boats, most built in the sixties with glass/polyester over fir/mahogany faced ply, up to 38', and delamination has never been a concern. The key is they were glassed as new construction, when dry, done properly by precoating the wood, using extended curing times, and making sure the resin was properly mixed. Adequate thicknesses over properly designed rigid hulls helps too.

Epoxy is toxic, expensive, and as Mike has experienced, not really needed in a whole host of applications where it has come to be seen as required for even the most basic boat. If you're building with BS 1088, bronze nails, custom made sails, sure, step up to epoxy. But why gold plate the hood ornament on a used chev truck? Lots of successful small boats have been built without any glass at all, and lasted many more years than they were truly needed or wanted. My best guess is both Mike and the friend he eventually gives this boat to will get all the use out of it they want before it rots away or fails. Boredom and a lack of interest/care kill many more small boats than compromises in construction materials.

My point is that polyester, done properly, is perfectly adequate for a small boat of the class under consideration, and will improve both its appearance and longevity without compromising the objective at hand.

[Memphis Mike]

Thanks again Conrad. smile.gif I guess I should have
included you in the title. The boat is going to
have a traditional lug rig. smile.gif

[ 12-15-2002, 09:03 PM: Message edited by: Memphis Mike ]

[On Vacation]

SO many ifs, so many redos, So many stories.

[Dave Fleming]

Shane,

Well answered Dave... gawd your getttin polite in your dotage mate!! Not just polite but understanding of those poor miscreants that have been seduced bye the 'Dark Side'. :rolleyes:

Last time I used Bondo on a true carvel planked wooden vessel was in about 1964.
In later years I read some unfavourable comments about poly-googe and often wondered about that vessel. I picture me as the shipwright doing some below the waterline work and coming upon those ***deposits*** of poly-googe and wondering out loud to no one and everyone within earshot...'who the hell slopped this shite in here?'.
My tender sensitive wooden boat soul cringes at the thought! redface.gif redface.gif

[ 12-15-2002, 11:04 PM: Message edited by: Dave Fleming ]

[WFK]

Conrad, I doubt very much that there is really that much difference in price between polyester and epoxy when you're talking about a boat the size of the one that Mike is building, yet the difference between the two products is really night and day. Why compromise? And why, if one is willing to take the time and effort to build these projects, would you want to use an inferior product, and when you're talking plywood construction, polyester is. Epoxy is stonger, much more flexible, as well as workable in all but most extreme temperatures, better saturation,... hands down much more user friendly.
Knowing then what we know now I'm sure that all those tollycrafts that you say are still hanging around, if built over, would be using E-P-O-X-Y

Bill

[imported_Conrad]

Gents, I'm not claiming polyester is the best- the key word here is adequate. And the project at hand doesn't need to satify our requirements, but Mike's. And it's time for a little rant, so sit back! :eek: smile.gif

To follow the prominent line of thought, why not upgrade to epoxy from polyester? And while we're at it, replace that fir ply with some 5 ply BS 1088 Meranti, and the stainless fastenings with bronze square drive screws with honduras mahogany bungs that match the mahogany in the rails and chines? We'll need some catalyzed primers and a base color/clear urethane paint job- the local autobody shop can spray it out in their booth so the finish will be mirror smooth! What?!! It's going to cost a grand instead of the $100 Mike had laying around for a fun little weekend project? Well hell, who is he, or I, to want to build anything less than the best- might as well go have a beer on the couch. Forget the damm boat. You say it's just another $50- I say it's a fifty percent increase in the cost of a project and a first step down the road that kills the idea.

Not recognizing that a consistent and sensible approach to a project has value to my mind suggests that one isn't really thinking things through, or is caught up in an elitism that does little to promote either a fellow forumite's enthusiasm, or the hobby as a whole. If you bring me your $80,000 Porche race car for paint, $10,000 is a good starting budget. The wife's $1500 Toyota certainly doesn't merit an industry standard $2500 paint job, let alone a $1000 job, and if you think it does, we'll talk, because my business is all word of mouth, and my reputation as a fair and reasonable guy is at risk.

I've made a lot of money and friends by meeting people at their needs, not mine, and by understanding that there is a balance and appropriate level of standards/perfection for each individual and project. That's true here too- the only boat that brings fulfilment and joy is the one that gets completed and used. Wasn't there just a thread about dumping a project sailboat that had gotten out of hand? It sounded like he was using only the finest materials and workmanship.

Truth is, there are a whole lot more fir ply and polyester boats being used on the water than there are bits of floating art, and history has already proven that as a practical matter they last more than long enough. And besides, should something fail, it's just an opportunity for another project! ;) :D And yes, Tollycraft might have used epoxy had they been built five years ago, but they were built 40 years ago, with polyester, and are still going strong!

Now, go check out my "art" thread in Misc. non boat, and see my softer side! :rolleyes: tongue.gif

[Frank Wentzel]

For what its worth; I had most of the polyester-glass delaminate from the plywood deck on my Egret. It came off in 3 - 4 foot long strips. The boat was professionally built. I would not waste my time and effort over a price differential that couldn't be much over $25 for the whole boat. :(

/// Frank ///

[stan v]

Oyster, we need your experience.

[Memphis Mike]

Thanks again for your replies guys. I still
think polyester will be adaquate for this
boat and that's what I intend to use. ;)

[ion barnes]

So this is what Oyster is upset about. Mike, I have used Bondo and fairing putty as the need arose and the part about sanding, well I use a sanding board with 36 grit, it doesn't load up quickly and the finish is acceptable for overlaying or finish sanding. The hollows you speak of are nothing and its conceivable that you will be smearing a thin skin of filler before the paint goes on.