Refinishing rudder, tiller and daggerboard this weekend

Webfoot1

Active Member
#22
You need a digital scale to get the epoxy mixed correctly. The pumps used in the West System are crude at best. Excess heat is usually caused by too much hardener but ambient temperature also plays a role.

The #105 epoxy resin is mixed in a 5:1 ratio with the #205 and #206 hardeners, and a 3:1 ratio with the #207 hardener.
 

L&VW

Well-Known Member
#23
You need a digital scale to get the epoxy mixed correctly. The pumps used in the West System are crude at best. Excess heat is usually caused by too much hardener but ambient temperature
also plays a role. The #105 epoxy resin is mixed in a 5:1 ratio with the #205 and #206 hardeners, and a 3:1 ratio with the #207 hardener.
The pumps sorta worked the first time, then went downhill in a hurry. :confused: Save your money. While it hasn't happened to me, don't let one drop of hardener get into your container of #105 or, over time, you'll have a solid block of epoxy. :(
 

Webfoot1

Active Member
#26
I’ve never had trouble with West pumps. I’ve found them to be reliable.
I did not mean they they don't keep pumping, I meant that you can't use them tomeasure out a accurate amount to provide the correct ratio. They do work to getyou in the ball-park so to speak but using a digital scale will save you wasted material and money in the long run.
If you remember your chemistry class any deviation from mixing the exact ratio of chemicals does nothing to help the reaction and just wastes expensive chemicals.
 

Ghost Rider

Planing into eternity...
#27
They do work to get
you in the ball-park so to speak but using a digital scale will save you wasted material
and money in the long run.
If you remember your chemistry class any deviation from mixing the exact ratio of chemicals does nothing
to help the reaction and just wastes expensive chemicals.
HaHa, Webfoot1, excellent observations!!! {Think Sherlock Holmes here...} Nothing worse than realizing that your resin pot is kaput while it's still halfway full and the current step in your project is incomplete, LOL. :confused:

As for chemistry class, I must admit that I don't remember much of it... not only due to age-related CRS, but also because I was stoned 90% of the time, while my friends & I concentrated upon explosives, not resin formulas. :eek:

Say, is that the original James Bond (Sean Connery) in your avatar? Or is it someone else? Kinda hard to tell on this computer, maybe I should go back and watch some early Bond flicks to get a clue... doesn't look like Ursula's hair color, but the body measurements are about right, LOL. :cool:

MIGHT BE SOME OTHER SHOW, I KNOW THERE WERE A FEW WHICH FEATURED BOATS, DIVING, AND SKIMPILY-CLAD BATHING BEAUTIES... :)
 

Webfoot1

Active Member
#28
1965 James Bond Thunder Ball. Movie had it all, underwater diving fights, skimpy clad women, hydrofoils for the bad guys and a swimming pool full of Sharks, not Sea Bass with lasers strapped to them. I miss SPECTRE the Red Menace, things have not been the same in movies and novels since the Berlin Wall fell.
 
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Ghost Rider

Planing into eternity...
#30
1965 James Bond Thunder Ball. Movie had it all, underwater diving fights, skimpy
clad women, hydrofoils for the bad guys and a swimming pool full of Sharks, not
Sea Bass with lasers strapped to them. I miss SPECTRE the Red Menace, things have
not been the same in movies and novels since the Berlin Wall fell.
All part of the globalist plot, LOL... gotta keep today's youth brainwashed with sociopolitical themes. I too miss the days when movies & shows were made solely for entertainment, the political/slash/globalist bankster propaganda produced today doesn't cut it. :confused:
 
#31
just trace your old rudder on a piece of oak and cut it out and sand where necessary, its even cheaper than buying the epoxy. i have done this for both my sunfish, centerboard and rudder then poly when finished sanding. good luck!
 

mixmkr

Active Member
#32
If you remember your chemistry class any deviation from mixing the exact ratio of chemicals does nothing
to help the reaction and just wastes expensive chemicals.
A common mistake of those using epoxies. It's a molecular matchup and any excess of either is just waste. This thought I'm believing, comes from adding extra MEK to polyester resins...which WILL make it "kick" faster.
 

Webfoot1

Active Member
#33
Also makes a poor clear coat as you can't get the epoxy off easily to refinish a wood part.

Remember the bumper-sticker your chemistry teacher had on his car. . .

'A Mole is a chemist's best friend!'
 
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mixmkr

Active Member
#34
Actually, I believe West does have a UV resistant clear coat. I've used the regular with decent success, keeping it out of the sun for prolonged periods. IOW, my mahogany rudder is glassed and coated with West.
But I agree, removing West to refinish a wood part, borderlines on futile. The epoxy also has a tendency, as you know, to absorb into the wood... why it's great adhesive as well.
 

Webfoot1

Active Member
#35
Epoxy makes a good wood filler/sealer if you put it on and then immediately
scrape as much off as you can with a card.

Spar Varnish is about continual upkeep but I kind of like it.
 
#36
Oh, boy...
Firstly, "I don't think a crack repair with cloth or tape is going to last." It won't if you use polyester, you need to use epoxy. In my experience WEST is the most reliable and controllable, and easily obtainable -- yes you need the pumps.
For structural repairs epoxy/cloth is often needed, but don't make things fatter, reduce the thickness of the wood before glassing.
Yes, epoxy can overheat, so can polyester if you add to much hardener. Epoxy works differently than Poly, you have to get the proportions right, adding more catalyst to epoxy just makes it go sideways.
Purchase the correct "speed" for you application, WEST makes really slow, slow, fast, really fast, epoxies. The fast epoxies will light up pretty easily on a hot day. Certain fillers, like Microlight, make it kick faster.
For a structural filler repairs use Cabosil (can be under different names, it's fumed silica), it's a bitch to sand. For ease of sanding use Microlight.
Threaded rods kinda work, buy since they're on centerline they have much less resistance to bending than glass fiber cloth in epoxy on both sides. Resistance to bending is a crucial thing for a rudders on an unbalanced rig like a Sunfish.
 
#37
I've been using the pumps for over forty years as a professional boat builder and never had a problem.
=====
"You need a digital scale to get the epoxy mixed correctly. The pumps used in the West System are crude at best. Excess heat is usually caused by too much hardener but ambient temperature also plays a role.
The #105 epoxy resin is mixed in a 5:1 ratio with the #205 and #206 hardeners, and a 3:1 ratio with the #207 hardener"
====
That 5/1 ratio is for volume.
For ratio by weight:
Resin weighs 9.6 lb/gallon and 206 catalyst weighs 8.45 lb/gallon
By volume the ratio is 5/1 resin/catalyst, so 1 gallon of resin requires .2 gallons of catalyst.
.2 gallons of catalyst weighs (8.45 x .2) = 1.69 lbs
So the resin/catalyst ratio by weight is: 9.6/1.69, or 5.7/1
 
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