Wooden dinghy boat building tips

cinnr

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I'm going to be building a PT11 as soon as the kit arrives from CLC. I'm planning to build it in my unheated garage...which I understand may be a problem with epoxy.  Any tips and/or things to avoid during the build process?

 

Pinching

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Depending on your location, heating the garage may be possible with electric space heaters or similar.  Warm and uniform temperature will make the substantial epoxy work (and subsequent varnish work) more reliable (and more comfortable).  Insulation is not particularly expensive or difficult in unfinished spaces, and a 120 or 240v heater can warm things up pretty nicely.  If cost is critical, do the work when it's warm.

 
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The Q

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Keeping the epoxy at the right temperature is the main thing,, Storing it in a box with a heater inside meant for keeping home brew beer barrels warm is what I'm planning to do for the next time I have to build something.. SWMBO wasn't happy with keeping cans of epoxy in the house... :D .

If the epoxy is warm you only need to warm the area of the boat you're working on while you're working, once it's applied and gone off, you can allow the garage / boat to cool till your next work session.

Oh painting , varnishing and or epoxying the whole boat will require warmth throughout the garage. so as said above space heating or working when it's warm outside is required.

 
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Autonomous

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Plastic sheeting to contain the heat around the boat and radiant heat are just two of numerous methods.

If you have access to an old refrigerator, an incandescent lightbulb inside will provide a warm place to store your epoxy.

 

cyclone

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For acceptable results, you need a reliable means to provide sufficient heat to apply the epoxy and get a good cure. Full cure may take several days. Next you want as much light as possible to see what you’re doing.  Nylok  wheel in a cordless drill makes a quick prep for fillets and taped seams. Cabinet scrapers and carbide (Sandvik) scrapers are great for smoothing. If you sand, wear a mask!

 

slug zitski

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I'm going to be building a PT11 as soon as the kit arrives from CLC. I'm planning to build it in my unheated garage...which I understand may be a problem with epoxy.  Any tips and/or things to avoid during the build process?
Epoxy is best handled at room temp

You need heat or else your build will   
be frustrating 

the classic.. curtains around the build …plus an electric space heater works well 

 

yoyo

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Its fairly easy to make an epoxy warmer box with an electric thermostatically controlled heating mat like the ones used for reptile enclosures.  Having warm epoxy will help wetting out fiberglass cloth and mixing additives.  Its also easy to make quick and easy epoxy post cure boxes for smaller parts using cardboard or insulating foam and duct tape. 

Nice video from Russell on glassing a PT11 when its cold using plastic sheeting and radiant heaters under the hull.  Mastering Epoxy with Russell Brown, Part 7 Fiberglassing the Outside of a Hull - YouTube   Right at the end there is a good description on wood outgassing and air bubbles.  He mentions reducing heating after epoxy is on the wood to minimize these and have the cooling contracting wood draw in the epoxy.  It's a good idea to follow this approach when coating wood with epoxy with or without fiberglass. 

Should be a fun project..

 

casc27

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If it's cold enough at your build location you can treat the whole construction as a pre-preg type situation. Build the boat in it's entirety with plenty of opportunity to reset from any fuckups and then let it all cure at once when spring comes.

Seriously, don't listen to me. But some of the sage advice up above should keep you on track.

 

slug zitski

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I'm going to be building a PT11 as soon as the kit arrives from CLC. I'm planning to build it in my unheated garage...which I understand may be a problem with epoxy.  Any tips and/or things to avoid during the build process?
If you decide to use a heater … your project may cycle hot,  cold with heater use .. remember the phenomenon of out gassing 

when a porous substrate like wood is heated , air is forced out .. out gassing 

when a hot porous substrate cools the opposite happens 

hence to achieve maximum Epoxy penetration  and avoid millions of tiny bubbles .. alway apply epoxy to the substrate during the cooling cycle 

 

Autonomous

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Cinnr, how much building/epoxy experience do you have? If not much I suggest you build something small using the same techniques as the boat. That is a proven method to achieving a better final product.

Cyclone mentioned scrapers, they're especially effective on green epoxy which is not something you want to sand.

 
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cinnr

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Actually I think the dining room may be part of the solution. Get stuff nice and warm there first.  Nice big table there and everything...

Thanks all for the helpful advice.

 

gkny

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The West system fast hardener will cure at fairly low temps (min of 40 fahrenheit).  I did some interior work in a boat and just left a lightbulb or two on during the night.

 

Nodrog

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Auckland
a far-infra-red panel heater is great, as is a beer brewers heat pad for warming up the resin. Don't apply resin then warm the ply, as above it gases and gives very dissapointing results. I also picked up an electric blanket for $10, was really useful for components, when vac bagging, put them on the blanket, and a sheet of cardboard on top, . I wouldn't use a gas/kerosene heater, fumes and condensating oils are not what you want.  You'll get more amine blush in cooler damp conditions with fast hardener, peel ply is great, as is just washing it off with water but adds another step.. 

Your best bet is to do it either in the living room or the dining room though! 

 

Autonomous

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In the house is quite civilized, actually.

I built 14' and 17' kayaks in the master bedroom. Protecting the floor is key. We used a 1/4" ply and tarp sandwich to protect the carpet.

 

2airishuman

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I'm going to be building a PT11 as soon as the kit arrives from CLC. I'm planning to build it in my unheated garage...which I understand may be a problem with epoxy.  Any tips and/or things to avoid during the build process?
https://www.westsystem.com/instruction-2/epoxy-basics/cold-temperature-bonding/

How cold is "unheated?"

Epoxy (and finishes) behave badly at low temperatures and at inconsistent, uncontrolled temperatures.  Dust and humidity over 95% are problems, too.  You have to have a good environment to get good results.  While it is possible to use epoxy in cold weather when absolutely necessary i.e. repair situations it is not conducive to quality boatbuilding.

If you use plastic sheets and electric heaters, keep in mind that it's easy to burn the place down that way.  Have good insurance.

If you use a kerosene heater while working with epoxy, the room air will contain combustion byproducts of epoxy fumes burning in the kerosene flame.  It will be a science experiment that could result in various acute or chronic respiratory conditions or allergic reactions.  Let us know how it goes.

A problem with epoxy in cold weather is that uncured epoxy sort of ends up everywhere and you get it on your hands and shoes when you're out in the garage four days later.  Messy and makes for additional exposures. 

You should be able to build a PT-11 inside, they're not that big

 

Russell Brown

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So good to see an epoxy question on a forum answered in helpful and sensible ways. other forums not so much.

Also interesting to see an Off Center Harbor video on youtube. OCH is subscription based, so people pay to watch. I didn't get paid to be the star, so happy to see it public. Anyone know the story?

Cinnr, let us know how it goes. Make sure you follow the manual!

 
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