I made a CF over balsa rudder with West Systems and it has a slight bend from impatience on my part, I aimed a light at it to speed up the set. Anyway, is it possible to heat it up and straighten it? If yes, how much heat?
Thanks
Don
Don -
is it the entire rudder “blade” that is bent - or just the rudder post?
If rudder post, - you can “spot” warm it with a good heat gun and (with gloves) bend carefully and slowly. Once it’s in position, running under cold water to lower temps is possible.
If entire “blade” - I’m not so sure, since you would have to heat both sides at the same time, then have someway to clamp into a jig to hold for cooling. You could give a try to placing in an oven and running temps up to around 200 or so and carefully watch for any bubbles from resin. Still need a way to hold it flat while cooling.
If blade is really badly bent, it probably is faster to just make a new one - considering time and effort to “try” to straighten without a guarantee it will meet your expectations. Big question is if you can place between something and clamp, once resin has softened up? Epoxy (most brands) will usually soften with heat (you can remove golf club head screws using heat) but how to hold straight? We’ve used black plastic garbage bags around dagger boards to speed up cure - just left them in the sun for an afternoon - but I think you will want to watch and touch as it warms up.
No sure I can help any further. I’ve still got some Mylar drafting film that has a roll-curl and I’ve tried everything to get rid of the curl - no luck. Back-roll, hand in south facing window with weight taped to bottom edge, re-roll and place in back window of car, very light/quick passes with heat gun - Nada ! So I can envision your disappointment.
Ummm - give it a try - one way or the other you “might” be building a new one. Let us know?
ADDED: You can email Gougeon Brothers (WEST System) and ask their technical support staff. Great bunch of people and very knowledgeable. They will probably want to know the lay-up schedule, but if they can’t help - it’s really trial aaand see.
I finally got arund to trying this. I set the oven at 200F and put the rudder in for 15min then put it across a couple of knives and put a 5 pound weight on it. When it cooled there was no difference except for a couple of small marks from the knife handles. I’ll use the rudder til I make a new one, it’s not that bad and I really can’t see it making much difference.
Don
Don,
I would think if you try the heat again, but give the rudder some bend the other way may help?
Andrew
I did. When I put it on the knife handles it was supported at each end with the weight in the middle. If it was going to bend it would have.
Don
would bending the shaft slighly where it meets the rudder blade help?
Ghost
I don’t think it would make any difference. The rudder has about a 1/16" curve from top to bottom. I don’t think it affects the sailing, it just bothers me knowing it isn’t straight. I’ll just ignore it til I get around to making a new one.
Don
A little bondo on the hollow side??? It will be aestetically nicer. Probably won’t sail as well not to mention heavier after all the work to make a light one.
Might be interesting to see how it sails. Maybe you wil find it scoops into teh water better on one tack and can use that to sail closer . . . . or something.
-Barry
I’ve pretty much decided to ignore it for a while. Nobody will know. Except maybe the 335 people that have read this post. I’ll have to kill you all. Nah, it’s easier to make a new rudder.
Don