rs 800 centerboard

[Banshee Ambulance]

Here is what the section you describe looks like: If Kevin says its a good idea then I might well do the same with my boat. All still a way off at the moment as I too will be cutting the case last. Interesting about the weight issue, I have not sailed an 800 for a long time so can't really remember!

[john_hamilton]

cool

[phil_kirk]

John,

Sorry i haven't looked at emails for a few days.

When making E numbers rudder stock sleave on the foil I thickened up the foil with a peice of cereal packet on each side and several layers of electrical tape on the leading and trailing edge. then parcel tape over the whole thing.  This was not vac bagged and was consolidated with two peices of 4mm ply clamped with lots of g clamps.  The sleave provided possibly a little too much play on the finished rudder balde but a bit of Jap tape or other packing material works fine and i get no vibration. room for a few repairs though.



the aim of the crash box is that the hull dosn't get pentrated if the board hits anything. The pad at top and bottom can easily be filled.

[john_hamilton]

is a rudder made without vac-bagging alrightish. how should i get consolidation? i (i have no bagging materials yet!

[ross_burkin]

It will be fine but it's hard to get decent consolidation compared to vac bagging. I recon it will be harder to keep the layup fair. The only method I know of is to wrap in bubble wrap, put a stiff board on top and add weights. Bubble wrap distributes the weight but will leave dimples which makes fairing harder.

You can vac bag very cheaply but it is best to be shown by someone who has done it before otherwise a balls up is pretty much inevitable.

[Phil Alderson]

I made all my rudders to date without vac.

Clamp the blank  leading edge up and you then put each layer on from the le and smooth down the blade to the trailing edge you can get the laminate quite smooth, with peel ply as the top layer you can get quite good consolidation.

One thing I have had problems with is the trailing edge going a bit wavy depending on how the cloth hangs. To avoid this on the last blade I made i clamped two wooden battens just where I wanted the trailing edge, these helped pull the cloth tight and kept the trailing edge straight.

[phil_kirk]

I can give you some bagging materials.

i had trailing edge problems with slippery's foils initially.

Clamping bits of wood at the trailing edge is a good idea.

I think i had an additional issue trying to laminate on to cedar which was perhaps more absorbent than i thought.  perhaps a resin with some filler would have improved the result.

[ross_burkin]

Maybe a sand bag would work?

[Phil Alderson]

I used sand when veneering a non cherub foredeck, and it was less effective than I was expecting.

I used small freezer bags of sand from a builders merchant and they just did not conform well to any kind of complex surface, they were heavy enough to distort the deck but did not put much pressure on sections that were not sticking down properly.

If you pull a vaccum you get atmospheric pressure pushing on all sides of your work at 14.5psi.
Even if you can only pull half an atmosphere with your pump that is still equivalent to about 3.5m of sand

[john_hamilton]

will an old vacuum cleaner work? iv got the foam core made and am awaiting carbon now

[Phil Alderson]

will an old vacuum cleaner work? iv got the foam core made and am awaiting carbon now

No, vacuum cleaners need the airflow to cool the motor so if you block airflow by connecting a bag it will quickly overheat and stop working, they also do not pull much of a vacuum.

Vacuum is not mandatory, you can make perfectly good blades without it, and you can make rubbish blades with it.

[JimC]

...on the last blade I made i clamped two wooden battens just where I wanted the trailing edge

Also, IMHO, a vital trick when doing daggerboard trailing edge repairs.

[ross_burkin]

Fridge pump.

[Will_Lee]

Fridge pump really does work, but be sure to blag a degassed one. If you dismember one you find on the street you will be putting CFCs in the air, which is fabulously bad for the environment and very illegal indeed. They do pull a good enough vacuum though.

[Banshee Ambulance]

We have proved that a modified, cheapo tyre compressor would be feasable. See the 'vac bac on a budget' thread in the tech section of the forum. That should have enough beef for a foil.