Jim Creighton wrote:

David, what thickness of closed cell foam would you recommend? A local yoga mat supplier offers 3mm and 6mm sizes.

David answered, under separate cover: "We used 10mm thick closed cell foam at about 20mm wide strips. I would definitely go for at least the 6mm thickness. Doing things the way we did it was very difficult sewing the webbing onto the batten pockets with the foam under it. But you are doing things different in wrapping the foam around the battens. I was thinking that if you try the foam and it is successful you could then maybe glue the foam to the battens with a covering such as very wide webbing over the top so as to protect the foam from chafe and UV."

Thanks for the photo. All is clear now!

Sails with batten-pocket "windows" could be retrofitted with short batten pockets of your design to close the window and protect the batten and mast paint at the same time.

Jim Creighton wrote:

I see. David, you say the foam strips are about 20mm wide only? I don't know why but that seems narrow. If I saw it up close I would better understand.

Remember that the foam is on the circumference of a 60mm diameter batten so it is just the narrow interface of the batten contact point with the mast which needs to be padded. In my case though because the battens are within pockets in the sail it is the actual sail which is making contact with the mast. On thinking about things a bit more I suspect that the webbing over the foam considerably reduces friction as opposed to just wrapping foam around the battens. Another reason why I get no noise from my battens and yard is that they are all held tight against the mast by the batten parrels. I am able to do this by having very long webbing batten parrels which can be pulled tight without creating friction when the sail is hoisted or lowered. So even with the sail to leeward of the mast the sail is still against the mast. This means that in those conditions when the yard and battens would normally swing away from the mast and then come back again with a 'thump', it just does not happen.

But if your batten pockets have windows at the mast you should be able to easily wrap some foam around the battens and fasten it in place. If you find this makes a difference and the experiment is successful then you can add some sophistication to the system to make the solution more permanent.

 

Jim Creighton wrote:

Thanks for this info. I have windowed batten pockets. I'll try the foam and tape method. Just found a roll of leftover closed cell foam to use.

David, could you give us  a few more details on your sewn-in system? How wide were the foam strips? How many pieces of seat-belt webbing do you use per batten? Just the one? How wide is it? Any photos?

On my sail battens, yard, and boom are all in full length pockets with the only opening in the pocket being at the point where the batten parrels are attached. For the battens the foam strips are about 20mm wide with a single width of seat belt webbing sewn over the top, that is stitched both sides. The yard pocket has two widths of the same. This is not an easy system to retrofit to the sail though unless one is able to hand sew the webbing to the batten packets. In my case the foam strips were put onto the pockets before the pockets were actually sewn onto the sail. You would not necessarily need to use seat belt webbing for this but we chose that because it s very durable and will hopefully last for a few years.

I can say though that the closed cell foam has made for a much quieter sail and is a lot more gentle on my painted mast, I don't get any of the batten and yard clanging that I used to with other forms of padding including plastic tube.

Another possibility for attaching the foam to the battens in your situation might be just simple cable ties every six inches or so. I know in New Zealand it only cost a few dollars to buy a packet of 100 cable ties. You would probably need to pull them really tight using a pair of pliers. 

If you have a look at my profile photos there are some pics of my sail which will give you an idea of how things are arranged.

Another system I used on my previous sail was to screw 20mm wide strips of polysuperslippery plastic, (I can't remember the proper name), to the battens and yard. This provided almost no friction against the mast but was not very quiet.

Thanks for this info. I have windowed batten pockets. I'll try the foam and tape method. Just found a roll of leftover closed cell foam to use.

David, could you give us  a few more details on your sewn-in system? How wide were the foam strips? How many pieces of seat-belt webbing do you use per batten? Just the one? How wide is it? Any photos?