Class Politics Hull Sanding - how much is legal ?

[49208]

The following passage is part of a longer how-to on making your bottom pretty on Fred's web pages.
My questions pertain to the second paragraph, underlined in red vs the Laser Class rules. Is the removal of ripples by sanding allowed ? If removal of ripples is allowed, what defines a ripple ? I see many new Vanguard boats in their first few months of ownship w/o any ripple or mould imperfection in the area of the mast step, but over time a clear impression where the mast step reinforcement is appears on the bottom, with a corrosponding change in the fairness/smoothness of the bottom in this area. Is this considered a mould imperfection or simply a case of the continued shrinking/curing of the hull producing a ripple which can be sanded smooth again ?



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Fred's article with the passage on hull sanding:

When all the repairs are flat and level with the hull surface it is time to begin working on the whole hull. Do not begin sanding the whole hull until you have finished sanding all the individual scratches. You need the shiny surface of the hull as a reference until the heavy sanding is finished so that you don’t make the surface wavy.

Now it’s time to get all the ripples off the entire hull. As long as you can smell styrene inside your boat the plastic is shrinking, becoming more crystalline and just plain getting uglier. You want to remove all the tiny ripples that your boat has developed as the plastic has continued to cure since it left the production mold. Remember that you are not attempting nor are you allowed to change the shape of your boat. This is a cosmetic repair, not a speed enhancement.
I usually start the whole hull job with 320 paper. Using a soft rubber block, I sand at 45 degrees to the centerline until the entire hull is a consistent, dull finish with all of the sanding scratches parallel. The reason to keep all of the scratches parallel is so that when you switch to another grade of sandpaper, you can sand in a different direction and know when you have removed all of the scratches from the previous grade.
It’s graffiti time. Use a pencil to make marks all over your hull. When Eric Faust does this part he creates cartoons and other nonsense, but lazy guys like me just scribble. The object is to make enough pencil marks so that it is easy to tell where you have and have not already sanded. Turn your sanding to the other 45 degree angle and shift up to your next finer grade of paper. Sand away all the pencil marks and then inspect your work. All the sanding scratches should run in the new direction. In areas where the old scratches still show, pencil and sand again.
Repeat the penciling and sanding with 400, 500, 600, 800, 1000, 1200 and 1500 grit papers. You can skip grits or stop at a heavier grit but your boat will not be as shiny if you don’t use the whole series. To make your bottom heavenly, you have to sand the hell out of it.

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Laser Class rule..............
11. HULL FINISH(a) Waxing, polishing and fine wet and dry sanding of the hull is permitted, provided the intention and effect is to polish the hull only. Polishing/sanding shall not be used to remove mould imperfections.(b) Sanding and refinishing of the hull with the intention or effect to lighten the hull or improve the performance, finish, materials or shape beyond the original is not permitted.

 

[gouvernail]

When we wrote that article, the passages quoted were considered and edited more than once.
There is a hard to define difference between fixing the shrinkage and removing molding imperfections.

I suppose the way the rule is written, we should all carefully inspect our boats when they are first purchased and carefully document al the mold imperfections we are never going to be allowed to repair.

The good news for all of us who play the game? The new Lasers recently being sold are awfully pretty and near perfect in appearance. They really don't have anything that could be described as "mold imperfections."

Post mold shrinkage of the plastic makes all Lasers (and virtually all plastic boats) become less smooth and fair than the day they were rolled off the production line.

As I see the rules, it is OK to try to put your boat's finish back in the same condition as the day it was puled from the mold.
It is NOT OK to attempt to reshape the hull, or otherwise attempt to make the Laser better than the day it was new.

Lasers are simple mas produced boats. Every Laser certainly could be made slightly better and faster with the addition of some money applied in the form of materials and labor. . The rule is there to keep skilled artisans from creating sailboats that look a lot like Lasers but perform just a bit better than Lasers.

examples of things other classes sometimes allow that we do not tolerate:
You cannot square the trailing edge of the hull. You canot add material to the inside edges of the cenbterboard trunk. You cannot trim off some gunwale edge to lighten the perimeter. You cannot tweak the shape of the bow where it enters the water. You cannot sand off the non skid so it hold less water. you cannot sand away the gelcoat on the sides and ends of the boat to improve weight placement. You cannot add additional bulkheads or remove un necessary reinforcements. You cannot remove the handrails and drill extra materiels away from the underside. You cannot rout out a gridword of grooves in the hull, fill the grooves with carbon fibers and re-fair the stiffened hull.

The Laser as it comes from the store and the sailors who want to race them are the bodies the rules are intended to protect.

You can shine and polish to make the finish as nice as the day it was created. Filling gouges, sanding off the excess filler and polishing will not make a Laser that is better than the ones that come off the production line.
In fact> Although the resulting surface may be smother, the act of sanding your Laser may only serve to slow it down. The stiffness lost by sanding away even that small amount of unsupported plastic in the form of gelcoat is probably measurable. Flexible boats are slower than stiff boats.

Summary: I do not believe you can make a special cheater better than new Laser by sanding the bottom.

 

[glasky]

We have an old Canadian Laser as a club boat and the hull, although now slightly heavy, has a marvelously stiff and fair bottom - Lots of newer boats have the mast base ripple you can see and feel. They also have a concave run in the keel line to the transom and are not nearly as stiff in the flat bottom pannels beside the c'case or in the sections near the bow.

Could you fill the stern concave, fill and fair the mast base ripples, reinforce the flat sections and bow (assuming you could get interior access via inspection ports etc) and still be Legal?

 

[gouvernail]

We have an old Canadian Laser as a club boat and the hull, although now slightly heavy, has a marvelously stiff and fair bottom - Lots of newer boats have the mast base ripple you can see and feel. They also have a concave run in the keel line to the transom and are not nearly as stiff in the flat bottom pannels beside the c'case or in the sections near the bow.

Could you fill the stern concave, fill and fair the mast base ripples, reinforce the flat sections and bow (assuming you could get interior access via inspection ports etc) and still be Legal?

Remember..."ONLY the ILCA Official Measurer can answer officially!!"

Having said that:

Your answer is NO.

Having said that:

You can do a lot for your particular boat.

First of all. The reasons the boat is stiffer than a new one are not evil cheap shoddy builder practices.

Some reasons old boats are stiff: ( note to chemists. If my over simplifications cause any of the following statements to become lies. please post better descriptions).

1. The older boats sometimes were built with less control on the resin. Some boats were lots heavier than others. Heavy and thick is stiffer than light and thin.
2. Old polyester resin laminates are stiffer than new freshly made laminates. Most of the chemical reactions happen in the first 45 minutes after catalization but, the resin continues to cure for a long time after that.
3. There are chemicals in the resin whose purpose is to keep the resin from becoming too brittle. Those chemicals continue to evaporate and when they are gone the resin becomes more brittle.
4. Summary of 2 and 3. Old hard plastic is stiffer than new soft plastic.

Another thing that matters> Old hard plastic is more prone to breakage. The soft new plastic has just a bit of pliability which can be a good thing and a bad thing>
Good:
The plastic itself is just a but stretchy and does not fracture as easily.
The laminate really gains its strength from the glass fibers. As long as the resin stays "stuck" to the glass fibers, the laminate remains strong and stiff. Slightly gooey plastic sticks and has just a bit of give. it may be possible to slightly flex a new lamintae without breaking the bond between the glass and the resin.

bad:
The laminate can flex in the plastic has pliability. Think about a fiberglass reinforced tire. it bends and flexes a lot and remains strong. You would not want to race a Laser made with tire rubber instead of polyester resin.

The stiff old boat:
The plastic may have a really tremendous grip on the glass...at first. If the laminate is flexed, the glass has to break loose or fracture. Either failure rsults in a flexible hull...permanently flexible.

I have always told people that the fastest possible Laser would be one purchased new, stored for a few years in a hot warehouse and then taken out for its first regatta.
I also believe the boat would fracture and become mush after very little use.

Back to the repairs:
You cannot add fillers or new reinforcements.
What can you do?
The answer to "Could you fill the stern concave?" is not but you can cause the laminate to regain its proper shape. Concave sections of the hull are caused by improper storage. Either the boat has been stored upside down and the hull has sagged or the boat has been stored with improper supports which caused it to bend.
Solution: You can support the boat by the gunwales and let it sag back to its proper shape. If time is an issue tou can fill the boat with heated water and the process will take weeks or days instead of years or decades. ( I reshaped a severely misshapen boat in 1998 by filling it with 6 inches of water and throwing a black tarp over tyhe hul. A few weeks later it was shaped like a new boat.)

Yoiur new boat concerns included>> "They also have a concave run in the keel line to the transom and are not nearly as stiff in the flat bottom pannels beside the c'case or in the sections near the bow."
This description sounds warning bells for me. New factory boats most certainly do not have this problem. Are these boats which have been stored upside down??

OK I have babbled enough here for a while.