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Amatuers building from foam/glass

Postby GuestMember on Tue Dec 16, 2008 9:31 pm

At the risk of being controversial i note the following trends in building Sabres.

The foam/glass boats currently commercially available are very well built and very stiff and fast.
Most other ply racing dinghies that had a strong amatuer building tradition have gone the way of being made principally from foam/glass. eg-Pacer, Fireball, Mirror, Enterprise, Paper Tiger, Sabot etc.

One of the attractions of the Sabre class is that amatuers have been able to build their own boat that will be competitive.

The quality of plywood available for building seems to have dropped right away.

So i wonder, is it time the class considered allowing amatuers to build from foam/glass . With glass on one side of the foam it has similar characteristics to ply in that it can be bent into shape , stitched together and then inside glassed.

Has anyone had similar thoughts or am i way off the mark?

Matt Westland
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Re: Amatuers building from foam/glass

Postby CDance on Mon Dec 22, 2008 10:44 am

GuestMember wrote:
The quality of plywood available for building seems to have dropped right away.

So i wonder, is it time the class considered allowing amatuers to build from foam/glass . With glass on one side of the foam it has similar characteristics to ply in that it can be bent into shape , stitched together and then inside glassed.


Is this a proven method? I mean, one used elsewhere in other classes? I've heard of Fireballs being male molded over foam but they have quite a fair amount of leeway in the weight department.

One of the advantages of the plywood stitch-and-glue method is that it's stood the test of time in two respects:
    * The boats last well - still 50 year old Mirrors floating around.
    * They are competitive.

I agree the getting good ply is becoming more difficult. But another way of looking at it is that the ply is probably the cheapest part of the whole boat. When I built my last Mirror I would have spent far more on the glue, resin and paint, than I did on the ply. So from that perspective if you need to purchase 2x ply sheets to get good set of panels, it's not a large overhead.
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Re: Amatuers building from foam/glass

Postby GuestMember on Wed Nov 06, 2013 10:54 am

I am all in favour for a lower cost Sabre that is home built, but the moulds need to be all the same shape.
I have also seen good classes destroyed by allowing different shapes into the class. Although some could argue that the wooden boats are home built and all different shapes, the ability to manipulate fibreglass is far greater and therefor proposes a huge risk to the future of the class.
Maybe the solution is to allow anyone to build a fibreglass Sabre, as long as the hull mould comes off an existing Fibreglass Sabre.
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Re: Amatuers building from foam/glass

Postby oztrack on Thu Nov 07, 2013 1:44 am

In 2010 I bought my first ply Sabre, because it appealed to me and I thoroughly enjoyed sailing it. I subsequently bought a GRP Sabre and I am enjoying it even more.

I sailed one design dinghy's in the 60s (in Europe) and am well aware of the issues around conversion from ply to GRP.

I chose the Sabre ( among other reasons) because it was a one design (so that all boats are the same). I recognize that tolerances acceptable for construction in ply (especially in 1974) were flexible, but GRP construction can mirror (and should do so) those boats produced so that they are similar in all respects to the original design.

I have no desire to become part of development class dinghy ( which the Sabre could become) and I would sell my boat if that became possible. I think others would think the same.

So, we need to retain the current rules about construction of boats in GRP according to the present rules and I would encourage all other members to support this.
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Re: Amatuers building from foam/glass

Postby Aten on Thu Nov 07, 2013 12:50 pm

Glass boats can do all the things that you guys have stated. The rules can be changed to accomodate them. But there are some facts that history has proven and should not be ignored.

*In every class that I know the introduction of glass production boats has made the ply construction obsolete due performance wether a real or percieved gain. e.g. Mirrors, Optimists and Sabres little sister the Minnow.

*Glass productions boats cost more. Currently in Sabres you do not need a fat wallet to win.

*Many classes have "died" as they tried to keep up with the times and introduce glass construction and alienating amateur builders.

*One of the main attractions to the class is that an amateur builder can build a competetive boat and have every chance to win a major regatta.

If its not broken why fix it. Glass boats are a bad idea for this class especially the proffessionaly built female mould variety. My opinion is that a "stitch and glue" foam sandwich hull could be a good idea but keep all frames and deck in wood. This type of construction is well within the realms of amature boat builders and will not add any extra cost and possibly be cheaper. This is basically the same as the current ply construction method of glass over ply on the hull.

Food for thought I hope.

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Re: Amatuers building from foam/glass

Postby GuestMember on Fri Nov 08, 2013 1:22 pm

I also agree, let’s keep the variations in glass boats to a minimum and make sure that any future boats are off current shapes.
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Re: Amatuers building from foam/glass

Postby Aten on Fri Nov 08, 2013 4:40 pm

I have nothing against glass boats. I have not owned a wood boat since my flying ant days. I am just concerned what the fibreglass boats could potentialy do to a class like this.
Obviously most of the guys spruiking glass boats in this thread already own one or get some finacial gain from glass boats. Correct me if I am wrong.

Can any one justify the low maintainence arguement for a glass boat?

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Re: Amatuers building from foam/glass

Postby Jack on Fri Nov 08, 2013 7:54 pm

Aten wrote:I have nothing against glass boats. I have not owned a wood boat since my flying ant days. I am just concerned what the fibreglass boats could potentialy do to a class like this.
Obviously most of the guys spruiking glass boats in this thread already own one or get some finacial gain from glass boats. Correct me if I am wrong.

Can any one justify the low maintainence arguement for a glass boat?

Craig

Hi Craig

I have built wooden Sabres and I enjoyed sailing it so much. But as I used it 3 to 4 time per week summer and winter. This extensive use caused the need to repainted and re-vanished the boat every six months despite being both two pack.

The maintenance for me was without doubt the reason for buy my fibreglass Sabre and I love the ease of it for me.

The good thing about the Sabre at the moment is Glass and wooden boats are comedpative with each other. I have seen this change very quickly in other classes when you allow fibreglass boats to manipulate the rules for speed, as can only be done in a glass boat.

So the issue for me is we keep a good hold on the variations of the boat, which I was under the impression was already in place when I read the Sabre Build manual, but it appears this may not be the case.

Lets not loose what makes the Sabre a great boat, wood and fibreglass boat that can sail against each other is very rare!
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Re: Amatuers building from foam/glass

Postby oztrack on Sat Nov 09, 2013 12:48 am

I strongly agree with Jack. We need to tighten the rules to avoid manipulation of fibreglass tolerances and maintain the one design status of the class.

It isn't only fibreglass boat owners who should be concerned, but also all those who have timber boats, if a "super" boat (but which measures) is designed and built, under the new and relaxed rules.

I'm not opposed to sensible and practical changes but this fundamental issue cannot be ignored. For example, I was amazed that transom (scupper) bailers were banned, when I bought my first Sabre, as we used them in the 60s and they are a simple, efficient and cheap alternative to through hull self bailers (costing $130 to replace when you leave them down when you launch the boat!!

Peter
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Re: Amatuers building from foam/glass

Postby GuestMember on Sun Nov 10, 2013 8:15 pm

It appears to me that we need to be very careful in changing this rule.
I for one agree with most of the arguments put forward here, we have a great boat, lets keep it that way and strive to have the FRP boats as much one design as possible.
How ever I so no reason why anyone shouldn’t be able to use an existing FRP boat to take the mould off and then they can home build, that keeps the FRP boats all the same shape.
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Re: Amatuers building from foam/glass

Postby oztrack on Tue Nov 12, 2013 1:10 am

I agree with the last poster, we need to be careful. We need to ensure that we have clear and equivocal rules which are easily understood and followed, so that both professional and amateur builders can follow them.

I'm not really sure that many amateurs will actually want to build a fibreglass mould, then a boat. I think that the best boost to numbers of boats in the class will be the production of a complete boat built in fibreglass by a producer who can price the boat at under $10,000. I believe that f that could be achieved, the class could grow even faster than it is at present. I think the future of the class is in fibreglass boats, though there will always be interest in home built timber boats.

Now there's a challenge!

Peter
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Re: Amatuers building from foam/glass

Postby Greg on Fri Nov 15, 2013 10:34 pm

While I understand the need to avoid the Sabre becoming a "development" class I disagree with the way the current rules attempt to do this and I believe the need to clarify and amend the rules on FRP construction is way overdue.

I appreciate that there are some reservations about the proposed changes, however i believe the confusion caused by the status quo is worse than the proposal.

The statement "The moulds must originate either directly or indirectly from master moulds approved by the SSAA" is completly open to interpretation and as such it is understandable that is has been largely ignored. My understanding is that both the YMS and Formula Sailcraft moulds were originally derived from wooden hulls so seem to be in contravention of this rule (please correct me if I am wrong).

Why is it okay for a FRP mould to be derived from a FRP boat but not from a wooden boat if both meet the rules?

In my opinion, the ONLY way that hull shape can be regulated is with actual measurements. If there is a belief that the current tolerances do not adequately constrain what is possible with FRP then we need to define the measurements more closely rather that making arbitary statments about direct or indirect relationships to other moulds.

Without such a set of measurements, I cannot see how the SSAA could determine whether or not to approve a new mould.

So if the majority of the top boats in the class are from non-approved moulds and if the only specifications that would allow the SSAA to approve a mould are the current class rules; is there any way forward other than the proposed ammendment?

Cheers

Greg
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Re: Amatuers building from foam/glass

Postby GuestMember on Fri Nov 15, 2013 11:07 pm

You are right on the money Greg, Very well said!
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Re: Amatuers building from foam/glass

Postby oztrack on Sat Nov 16, 2013 2:48 am

So, now is the opportunity to vote on this Rule change....each State has nominated 2 representatives to review these rule changes.

I encourage every member to consider them carefully, especially Rule 42 and to tell those representatives (do you know who they are, if not find out?) your opinion. If you oppose them, you need to tell the people involved, or they will recommend according to how they think. That may not be in the best interest of the class.

I encourage you to think seriously about the change proposed to Rule 42, the present wording is not what is needed and does not achieve what the Class needs, but it should be reworded, not cancelled, as I am hearing some State representatives are suggesting they should be. Please tell your representatives that this rule needs to be carefully considered and replaced with a ruling which will ensure the maintenance of the One Design aspect of our Class.
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Re: Amatuers building from foam/glass

Postby Greg on Sun Nov 17, 2013 9:57 pm

GuestMember certainly has a lot to say. It would be easier to keep track of the thread if everyone could log in or at least sign their name at the end. It is hard to gauge if there are 4 people having this conversation or 20 - Thanks

So in reply to "GuestMember":

It sound great to use measurements, but as fibreglass can be manipulated in anyway you want, it is not possible to have enough measurements.


As i understand it, the core concern is that FRP boats will make shapes that wooden boats cannot (of course wooden boat builders would not attempt to manipulate the rules :) ). If that is really the issue then I cannot see it is too difficult to define the limitations of wood and add them into the measurements.

I have not got access to the "secret" rules so am not sure what measurements are currently in place, but I would have thought that by:

  • defining maximum curvatures
  • defining number of inflections (times the hull changes from concave to convex)
  • defining the ratio of compound curves (how much it can bend in one axis when it is bending in the other

the FRP designs could be restricted to shapes that are possible in plywood.

Cheers

Greg
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