Dart 15 Forums

Hello,

over time a bit of rainwater accumulates in the lower mast. Either I take the mast down and occasionally drain it or I drill a small hole at the bottom of the mast and plug it before going sailing. The last solution is a bit rough but fast and efficient.
Do you also have this problem and what solution did you choose? How do you (I) make the mast watertight? It seems complicated.

Thanks

I just found the article Leaky masts by Bob Carter. Thank you Bob!

Good show. Please tell us which fix you used and how you got on.
Regards
Bob

Hi Bob,

I think I'll first try the last idea you describe of installing a gasket between the two parts of the mast. I might try teflon tape.

If it fails to keep it watertight I'll go and drill a small hole at the base of the mast above the mast heel casting.
Do you know how far the casting goes into the mast?
I might just double the distance between the mast base and the rivets but it would be nice to have an accurate measurement to aim just above the casting. Hopefully the castings are all identical.
I would keep the hole plugged while sailing but possibly with something else than a screw. Thanks.

Cheers, Thierry

The original 2 piece mast was sealed at the joint areas either side of the sleeve by squashing a mixture of epoxy and filler between two polystyrene plugs, the tops of which were then covered with a layer of epoxy paste. Over a number of years with the expansion of the aluminium wall and the brittleness of the epoxy the seal can start to leak. Current 2 piece masts use modern adhesives that are far more flexible and do not create the same problem. Provided the mast sleeve can be removed the old seals can be knocked out and replaced using these modern adhesives. Over the years the mast sleeve has been secured in either the bottom or top mast section.
One way of removing water trapped in the bottom section is to remove the mast heel casting by drilling out the rivets . Above the casting inside the mast will be a sealing plug covered with layer of sealant. If you drill through this plug with a small hole you will entre the sealed section and potentially drain the water, by either drilling a second hole to allow air in or applying internal air pressure in some way. With the water removed reseal the holes drilled using a modern adhesive.
This does not solve the problem of where the water is getting in but by applying air pressure via the bottom of the mast you will most probably identify the source of the leak further up the mast.
Hope that helps

Brian thank you very much for the detailed reply,

unfortunately on my mast the sleeve is mounted on the top part of the mast making the bottom part a receptacle for seeping rain water.
If you drill through this plug with a small hole you will entre the sealed section...
I guess the sealing plug would be some sort of silicone smeared on top of the casting before mounting in order to ensure air tightness?
The question for me would be how far from the mast bottom should I drill to enter the sealed section? I would first try to install a cotton wick to drain the water if it doesn't want to drain by gravity.
Following Bob's idea I could also try a butyl rubber gasket in the joint between the 2 parts of the mast.
I'll keep you posted.

Cheers, Thierry

Hi, These are the simple steps Windsport would suggest to try first as your sleeve is in the top section of your mast
1) Remove the water from inside the mast by removing the mast heel casting and accessing the lower plug and removing the water by the means suggested.
2) measure the gap between the bottom of the sleeve and the plug in the lower mast section when the sleeve is fully inserted. This is normally a few cm.
3) Use silicon sealant or similar to add a second layer of sealant to the top of the plug especially around the wall of the mast . There are various ways to do that , but one way is to stand the mast vertical to apply the sealant using a shaped plate on a stick or just a stick to spread it around the plug surface.
4) When the the mast is assembled there is normally a gap between the plug and the bottom of the sleeve. This can collect water when the mast sits upright as rain water runs down the mast. if the gap is significant you could drill a small hole in the back of the mast through the web section accessing via the sail groove to drain any water collecting in this area. The hole position needs to be carefully measured so it is just above the sealed plug.
Hope that helps. B

Hello,

I have had my lower mast turned upside down for quite a few days and it drains very slowly. I would probably have to wait for a few months to drain it dry. That makes sense as the leak is very small.

I have decided against drilling just above the top plug of the lower mast as it seems to me that the rain water would still keep seeping into the lower mast. Instead I will try to reduce the amount of water entering into the lower mast with a few turns of teflon tape around the sleeve and/or a rubber gasket at the interface of the two sections of the mast.

My plan is to drill a 6mmt hole through the mast above the lower plug of the lower mast to have a permanent drain as described by Bob. I would open this drain when required to empty the lower mast.

I have determined that the mast heel casting is inserted about 1" into the mast.
Does anyone know the thickness of the lower plug located on top of the mast heel casting as I would like to drill the drain hole as close as possible above that plug?

Thanks

Cheers, Thierry

Hi Thierry,
There is a picture of the heal casting on the Windsport website:

https://www.windsport.co.uk/product/spr ... -included/

Tom or Brian Phipps from Windsport could give you the depth of insertion.
Regards
Bob

Thanks Bob,

my question is not so much the depth of the heel casting which is I believe about 1" inserted into the mast but the thickness of the plug located on top of the said casting. I just would like to avoid drilling through the wall of the mast into the plug.

Cheers, Thierry

the exact position of the plug will of varied over the years of manufacture. Whilst Windsport do not recommend drilling any holes in the sealed mast sections of the mast probably 30cm above the end of the section will leave you above the plug. The question would be just how high above the plug.

Thank you very much Brian for all your comments,

I drilled a 3mm hole 25cm up from the bottom of the mast. I measured the distance between the hole and the top of the plug with a piece of wire and found it to be about 5cm.
By weighing before and after I drained 2.3l of water accumulated over a period of 7 months.

Cheers, Thierry