I want to run an adjustable outhaul on my boom but it is only a wave boom (suits all my sails, which are small) so it doesn't have the pulleys on the clew end.
I have removed the plastic clew end and tried a clamp on pulley system but it doesn't stay put, even with rubber padding underneath.

Does anyone have a broken boom with a three pulley system I could have?
If the arms of the back end are narrow enough I could use the whole back end, or some booms such as Aeron and prolimit have a plastic pulley assembly which is riveted on to the back end (circular cross section) which I could simply remove and rivet onto mine.

My boom is a North platinum wave boom. So I'd need either a narrow carbon (24mm?) back end or the plastic pulley assembly that would fit onto a 26mm? back end. (Just guessing the measurements because I don't have the boom with me.)

Ideas welcome.

If you can get extension tubes (not the clew/pulleys, just the tubes) that will fit your boom, and a 3 pulley back end from anything else I can adapt it
Then keep your factory back end so you still have a standard waveboom if you choose to use it without the adj outhaul

Just a thought

If you buy the adjustable outhaul kit, it includes the 3 pulleys back piece

I spose you could put one on a wave boom. I might give that a try one day myself

That one that Gazman has sugested looks good better than the one that your running Anita!

Select to expand quote

stroppo said...
That one that Gazman has sugested looks good better than the one that your running Anita!

That's why I thought I'd try a different approach!

Yes, thanks Gazman, that's exactly the thing I am looking for, and a good price too.

Select to expand quote

GazMan said...
This one has three pulleys and may be worth a try:
http://www.surfsailaustralia.com.au/showProduct/Windsurfing/Boom+Accessories/440797/Surf+Sail+Australia+Back+End

So I bought one of these, now I need some advice from before attaching it to my boom. The boom back end clips onto my extension tube, but needs securing. There are two holes in the back end for this purpose but my boom only had one rivet for the original back end. The second hiccup is the band in my boom tube has a slightly greater radius than the back end is made for, and my boom tube is of slightly smaller diameter than the back end is made for.
So, question one - how easy is it to drill holes in a carbon boom end? Is any special technique required?

I don't have a rivet gun. Can I use self tapping screws? How strong is carbon at holding screws? Will it withstand enough pressure that I can tighten the screws sufficiently to close the (3mm gap) between the boom tube and the back end assembly at the point where the (rivet) holes are?

The screws really only need to be strong enough to prevent sideways slippage of the back end. The force applied by the outhaul will hold the back end onto the tubing.

Thanks

I would be more inclined to use some "knead it" like epoxy putty to fill your gap and secure the back end. My worry with extra holes and forcing it to take shape would be introducing cracks in to the carbon.
A photo of the situation would help with solution suggestion.

Select to expand quote

lao shi said...
I would be more inclined to use some "knead it" like epoxy putty to fill your gap and secure the back end. My worry with extra holes and forcing it to take shape would be introducing cracks in to the carbon.
A photo of the situation would help with solution suggestion.

Photos as requested:
This one shows the new back end and the boom tube - not quite the same bend curve diameter


This one shows the new back end clipped into place. The photo isn't square on. The amount of boom tube showing below the back end is roughly double the gap between the two parts


The back end showing holes for rivets. Two in the new part, one in my boom end.


The chips in the boom tube were caused by the clamp on metal pulley assembly I was trialling. I had it padded out with EVA but it kept slipping when sailing forces were applied.

Suggestions please?

The holes on the back are for rivet's, I'd would recomend using Stainless ones

Select to expand quote

elmo said...
The holes on the back are for rivet's, I'd would recomend using Stainless ones

I don't have a rivet gun. Can I use self tapping stainless screws?
Is it safe to drill a couple of holes in the boom or will this weaken it significantly?
How strong is carbon at holding screws?
Will it withstand enough pressure that I can tighten the screws sufficiently to close the (3mm gap) between the boom tube and the back end assembly at the point where the (rivet) holes are?

screws will be fine. i have one i used screw on 5yrs ago still going strong

Rather than drill 2 new holes in the carbon tail piece (thus creating a total of 3 holes fairly close together and weaken its carbon structure unnecessarily)
- I would drill a central 3rd hole in the nylon clip on section, that lines up with your old tail piece hole. (this might sound a bit obscene to a non windsurfer)

As you rightly say, it only needs to prevent it from slipping sideways, so don't weaken the carbon.
I agree with Elmo, re using rivets. The carbon wall won't hold the thread of a self tapper very well. It would be too susceptible to over tightening.

Or another option is to drill through the whole tube and use a mushroom head bolt and nylock nut (nut being on the plastic side), all s/s of course.

Rivets would be the easiest though, although im always wary to rivet carbon, thinking that when you compress the rivets the carbon is just going to crack apart. Probably wouldnt , its just always in the back of your mind

Select to expand quote

Bondalucci said...
Rather than drill 2 new holes in the carbon tail piece (thus creating a total of 3 holes fairly close together and weaken its carbon structure unnecessarily)
- I would drill a central 3rd hole in the nylon clip on section, that lines up with your old tail piece hole. (this might sound a bit obscene to a non windsurfer)

I like this idea. Good lateral thinking (or in this case central)

You've probably already thought of this, but hows your carbon laminating skills? That would bring it up to the right curve. (got some spare if you need it)

If you hacksaw off those extra pieces of the new backend, either side of the pulleys, does that make the radius more manageable?

This might get it closer to the carbon, so that you can get a rivet into it.

Select to expand quote

pepe47 said...
You've probably already thought of this, but hows your carbon laminating skills? That would bring it up to the right curve. (got some spare if you need it)

Carbon laminating skills = 0

I have wrapped the tube with some self adhering silicone tape. It tidied up the rough patches, bulked up the diameter a bit, and should provide some grip for the back end piece to reduce movement.
I have also found a rivet gun, so now just need a stainless rivet and Bob will be my uncle!

Anita, I have a rivet gun you can borrow, don't think I have any stainless rivets though.

Select to expand quote

paddymac said...
Anita, I have a rivet gun you can borrow, don't think I have any stainless rivets though.

Thanks, It turned out my Dad had given one to my son, who actually knew where it was!

Select to expand quote

Windxtasy said...

paddymac said...
Anita, I have a rivet gun you can borrow, don't think I have any stainless rivets though.

Thanks, It turned out my Dad had given one to my son, who actually knew where it was!

Ah, the joys of a tidy shed

Your current method relies almost exclusively upon the rivets for retaining the part and stopping it from twisting under very large load from outhaul. All good if it fits right - but it doesn't.

You need to fill the gap and also have that fill assist in retention of the part.

Fill the gap with JB Weld, or Devcon 10110. Both are epoxies with a very high strength as a filler and for bonding.


I would fill all the inside, press it on, then wipe off excess. After 24 hrs, drill the holes for 2 rivets and rivet on with stainless pop rivets.

NOT alloy rivets as they will corrode in carbon.

THEN, in doing the above, the rivets are the icing on the cake, not the be-all and end-all

Anita if you can't find Devcon in the less than 500gm tin ($150!!!) I have some small qty's and guess what a half full tube that would be just right for that job.

I also have stainless rivets but unsure of the shank length

Select to expand quote

Darkplague said...
Or another option is to drill through the whole tube and use a mushroom head bolt and nylock nut (nut being on the plastic side), all s/s of course.

Rivets would be the easiest though, although im always wary to rivet carbon, thinking that when you compress the rivets the carbon is just going to crack apart. Probably wouldnt , its just always in the back of your mind

Do not drill holes on the inside of the extension as that is under tension while loaded.
Do not cut the ends off of the fitting as thay help with reducing the twisting affect when loaded.
Rough it up & pack it out with Kneadit, cheapest & easiest method, drill the extra hole in the fitting & yes Bob will be a rello
With extra packing out of Kneadit you could probably get away with a self tapping screw if it's thick enough.

Note: the down side to St St rivets is they apply a lot of pressure around the hole as they pull up to shear the shank which can shatter the carbon around the hole leaving a larger area damaged & weakened

Thanks for all the helpful suggestions.

Shane gave me a similar end piece with only one rivet hole - solved the problem of drilling more holes, and provided a more professional looking result. Thanks Shane!

I reduced the dead space by wrapping the extension end with self amalgamating silicone tape. Neatened up the extension and provided a lot of grip.

Called in at a yachting supplier to get a stainless rivet and they very kindly applied it for me. It had a long grip so hopefully didn't squeeze the carbon too tightly.





Now for some wind to test it out...

That looks like a much better result this time Anita