New Boats--Let's see em

[raceboat61-S]

Flexing

Flexing is usually a GOOD thing. Racers that have raced both the brittle pure carbon fiber boats and wooden boats will tell you that flexing gives a better ride. If weight is critical for your boat/motor/driver combination you may have to sacrifice the "ride" a wood/epoxy boat will give you.
Mike Marshall Raceboat61-S

[hydroplay]

If flexing is such a good thing, why don't you leave some crossframes or stringers out of your next boat and see how it works? Or find some 1.5 mm ply for decks? Or mount your steering wheel on a pedastal rather than a dashboard that ties the cockpit sites together?

While ride "feel" may be nice for a driver, the purpose of a hydroplane is to go around the race course faster than the other guys. Funny you didn't mention anything about the actual performance of a stiffer hull, only a subjective quality virtually irrelevant to the major mission. As one who has many times put new decks on a 3-5 year old boat to stiffen it up again and see a performance gain in cornering, I know stiffer is better! Perhaps you can get to the point where it would be too stiff, but I can't imagine that in my experience. Guys spend hours working on their bottom contours just right, only to want their hull to flex and distort their work? I don't think so!

The thread was on who uses what species of wood and in response to some guy who claimed that Sitka spruce was god's gift to hydro builders. It was to point out that most testing for wood samples was done on a size basis but that lighter species may have better properties when compared on a weight basis and that weight is more of a concern to us than size. I gave some engineering basis for this. It seems that most hydro builders are using lighter woods than Sitka already, yet some guy without a record of building contemporary, winning hulls still says that Sitka is best. If you want to believe someone's opinion, good for you. I'd rather believe actual facts, figures, math and results.

[raceboat61-S]

OUCH ! I appreciate you're fine post on the properties of various woods and the engineering considerations necessary in hydro construction but your response to my comment about enjoying some flexibility was a bit over-reactive. I built my first BU runabout in 1960....am currently building a 25 Mod/SSH hydro of obeche and okume. I have met with some success in the shop and on the race course. I still enjoy racing both runabouts and hydros in about 7 different classes. At 61 years old, I appreciate a bit softer ride. I enjoy the natural flexibility of my wood/epoxy boats. Mike Marshall, Raceboat61-S

[G Stillwill]

Some pics of the B Mod Hemp kit Im building for Ron Selawach and next is a Hemp BSH kit for myself.

[f8andbethere]

If flexing is such a good thing, why don't you leave some crossframes or stringers out of your next boat and see how it works? Or find some 1.5 mm ply for decks? Or mount your steering wheel on a pedastal rather than a dashboard that ties the cockpit sites together?

While ride "feel" may be nice for a driver, the purpose of a hydroplane is to go around the race course faster than the other guys. Funny you didn't mention anything about the actual performance of a stiffer hull, only a subjective quality virtually irrelevant to the major mission. As one who has many times put new decks on a 3-5 year old boat to stiffen it up again and see a performance gain in cornering, I know stiffer is better! Perhaps you can get to the point where it would be too stiff, but I can't imagine that in my experience. Guys spend hours working on their bottom contours just right, only to want their hull to flex and distort their work? I don't think so!

The thread was on who uses what species of wood and in response to some guy who claimed that Sitka spruce was god's gift to hydro builders. It was to point out that most testing for wood samples was done on a size basis but that lighter species may have better properties when compared on a weight basis and that weight is more of a concern to us than size. I gave some engineering basis for this. It seems that most hydro builders are using lighter woods than Sitka already, yet some guy without a record of building contemporary, winning hulls still says that Sitka is best. If you want to believe someone's opinion, good for you. I'd rather believe actual facts, figures, math and results.

Agree with everything you have written --though I could do with a little less sarcasm. However, the bottom line for bottoms is aluminum honeycomb. It is a skosh heavier than 1/4 inch bottom plywood of choice but is 10 times stiffer and it will allow you to do away with some stringers and deck frames which in the end will give you a lighter boat.

RB

[26V]

A/B Runabout

here's the runabout I have started. Work is moving along at a decent pace.

[daveracerdsh]

Flex

I have to agree with the previous post...A little flex seems to help a hydro get around corners etc better then a totaly stiff boat. Like I said in an earlier post, for a few years I had a small video camera mounted on dash of my D stock hydro...The last couple of nights I have been sitting around watching all the in dash tapes, and like I said earlier, both sponsons flex way more then people think they do. I am betting at least 3 inches...which sure seems to be a lot, as you cant move sponson at all when boat is on boat cart. Or you shouldnt be able to anyway. The force involved must be tremendous! My theory is that sponsons on a hydro, if they have some flex to them, act like shock absorbers on a car, absorbing impacts etc. Bob Wartinger had a race craft hydro, which i think was made or of carbon fiber or something along those lines. He was never able to get the boat to work...It was fine down the straights, but was a total handfull in the corners. Was this a result of being to stiff? I am not sure. It could be that boat had no "twist" built into it...not sure of that either. For the record, I put 3/4 inch in all of my boats. The carbon fiber boats seem to work in the slower smaller classes for some reason, such as ASH. I would suppose the same idea works for props. I have (or had) 2 Dewald round ear props, both of which are identical. Yet, one was at least 2 mph faster then the other. When I broke a prop shaft (of course you never have this happen when you are running a crappy prop) and lost wheel, I had Ron Hill look prop 2 over. He thinned it out a little....Just a hair...and it was now as fast ir maybe a little faster then prop 1. Is this a result of flex patterns? Who knows...but I bet there is a correlation to flex in hydros. Just some random thoughts.

[Lights]

Kevin, who's kit or plans are you building the runabout from? Keep us posted on how the building is going.

Mark

[daveracerdsh]

Runaboat

Looks nice. What kind of wood are you using? What type of glue?

[Richard K.C. Mo.]

What Is Is!!!

I have to agree with the previous post...A little flex seems to help a hydro get around corners etc better then a totaly stiff boat. Like I said in an earlier post, for a few years I had a small video camera mounted on dash of my D stock hydro...The last couple of nights I have been sitting around watching all the in dash tapes, and like I said earlier, both sponsons flex way more then people think they do. I am betting at least 3 inches...which sure seems to be a lot, as you cant move sponson at all when boat is on boat cart. Or you shouldnt be able to anyway. The force involved must be tremendous! My theory is that sponsons on a hydro, if they have some flex to them, act like shock absorbers on a car, absorbing impacts etc. Bob Wartinger had a race craft hydro, which i think was made or of carbon fiber or something along those lines. He was never able to get the boat to work...It was fine down the straights, but was a total handfull in the corners. Was this a result of being to stiff? I am not sure. It could be that boat had no "twist" built into it...not sure of that either. For the record, I put 3/4 inch in all of my boats. The carbon fiber boats seem to work in the slower smaller classes for some reason, such as ASH. I would suppose the same idea works for props. I have (or had) 2 Dewald round ear props, both of which are identical. Yet, one was at least 2 mph faster then the other. When I broke a prop shaft (of course you never have this happen when you are running a crappy prop) and lost wheel, I had Ron Hill look prop 2 over. He thinned it out a little....Just a hair...and it was now as fast ir maybe a little faster then prop 1. Is this a result of flex patterns? Who knows...but I bet there is a correlation to flex in hydros. Just some random thoughts.

I hope this thread continues a while, very good subject , may have something to do with safety also.
P.S. WHAT IS IS came from Bill Not Me.
RichardKCMo

[kws]

Mark,
26V is Gene lol .GENE is building this boat not me
he is using west systems epoxy
as far as the wood goes it lighter and stronger than sitka but i will let him tell you what it is ( hey i dont want to steal his thunder ya know ) lol

hint its very straight grained,

[proprider]

New DSH

New DSH boat that got finished enough to test at the last Region 6 race in Brighton Mich. Now in the shop getting finish sanded and painted in the next weekend
Joe 2-H

[Jeff Akers]

JDS Factory "South "

Jon Steen and I have been busy building some new boats, He's been at my place for a few weeks making a mess of my little shop

The first pics are of my new D boat going together wich will eventualy get Kevlar cockpit sides

[26V]

plan


Mark, Whats up?
The Plans are from Coop, with phone help for any questions from Jeff Scheffler. The wood is some we dryed in the kiln its cottonwood. Lighter then sitka spruce, very straight and clean. Just have to watch out for breaks in the grain. I over sized the stringers slightly to compensate for the relative strenght differences between the spruce and cottonwood. Works nice, and normaly takes screws very well.

Gene

[Jeff Akers]

More JDS "South"

This is Jon's new U.I.M 350cc Comp/Kilo boat going together