Rivets in Mast

I'm new here and hope this is the correct location to ask my question.

I have a Watkins 27 that someone in the past added a roller furl main. The sail is 4 feet short on a 10' boom. Looks more like a storm sail. The sail fills the roller shaft so there is no room to add a larger sail.

The mast is original with this add on. I was wondering if it would be ok to remove the furl system and replace all the rivet hole with screws. Would this weaken the mast?

There is no way I can use the present system.

Thanks for your help.

 

The mast wall thickness may not be enough for screws. Why not rivet the gooseneck?

 

I might have misunderstood what you're asking but if you intend to remove some or all of the roller furling system, then yes you can.

the rivets pictured are commonly called pop rivets or blind rivets and are very easy to remove with a good quality battery drill and a small nail punch or drift.

There is a central hole where the shank broke out - by drilling this with a drill a little smaller than the original hole, until you hit the remains of the shank. This will leave the walls of the rivet so thin that a sharp tap with a punch and hammer will remove it,

Repeat, repeat repeat.

will leave the remains of each rivet inside the mast, if there is no access, if you have dropped the mast you may need to drill the rivets on the foot and remove then replace (after de-riveting)

Once all the unwanted gubbins of the roller furl system is removed you will be left with holes, Yes you could screw them but as they were originally fitted with rivets, why not buy a rivet gun for about 10 bucks and just put rivets back - will be less obtrusive than screws.

Are you dropping the mast or climbing it?

 

Andy is right, normal practice is to replace the rivets with new rivets, but you only need the shortest ones available if there is only a single wall thickness. Maybe one length up if there is a sleeve or doubler inside the lower mast. Also get the correct grade and material NOT soft alloy ones the hardware shops sell, get monel ones from a chandler or professional fastener reseller. Ensure correct diameter too.

The reason rivets are better than screws is they fill the hole completely and smoothly. Testing on properly plugged timber and alloy masts has shown very little drop on strength under load. However if the holes are not filled, significant weakness becomes evident.

 

Thanks guys for the replies and help. I had not thought of replacing the rivets with rivets. I have to go to Houston near the end of the month. I see what I can find for rivets. I live in a very small town with little selection for anything.

Again thanks.
David

 

If you intend to use the holes again, I'd recommend a "nutsert" which is a form of rivet, but with threads for a machine screw or bolt.

If just putting rivets back in, use sealed ones, so moisture entry is controlled. Also insure the shank is off the same material, so you don't have a corrosion issue.

 

I intend on using the same holes. Can't see drilling new ones. What would be the advantage of using a nutsert with counter sunk screws over rivets? I understand using the same material as the mast.

Can anyone by looking at the photo tell me the make or the manufacture of this roller furler system? So far I've not turned up anything doing a google search.

 

The only reason you'd use a nutsert is to reattach something in the same holes. Other wise a self sealing rivet will do fine.

I'll bet if you look carefully, you'll find a manufacture's logo and/or name on that furler.

 

I've looked the unit over and there is nothing that would give me any idea on who is the manufacture. I did find a site that has a system similar. I email them with a photo of mine. Maybe they have an idea who made the furl system.

If you look at this photo you will see how the top unit is. There is no way to add a normal main sail with the topping lift so close. This is why I want to remove it.

 

Does seem odd that it is SO far off.

Its not only the space, but the number of turns on the worm drum at the bottom (or lack thereof) which would also prevent a wider sail - the whole thing is wrong.

I may be jumping to conclusions but
Could it be off e.g. some sort of Ketch rig -
You say 4' short on a 10' boom?
A 6' boom wouldnt seem to make any sense otherwise?

Possible someone ordered as an aftermarket kit (incorrect) - with the mast level in the yard something like that could be fitted in an afternoon and still have time to down a six pack or two before the pubs opened.

 

I had not thought of that. Good explanation on why it doesn't work correctly. Maybe I should have gone to the pub instead of buying this boat.

 

Don't worry about it - you'll soon get her back to factory spec.

Every boat has modifications;-

Sometimes it's a brilliant owner correcting an oversight by the designer other times its a foolish owner ruining hours of careful attention to detail at the design stage.

I've removed many a poorly executed 'add-on' only later to find 'Oh THATS what it was for - Doh' (So I don't throw them away or sell them 'till I'm sure )

 

I think this time a previous owner tried to re invent the wheel and it didn't work. I'll get her back to factory spec. Then the mainsail will be usable.

 

I received a fast reply for a company that I thought might be the manufacture of my furl system. Here is their reply.



"From your picture, it is possible that this system was manufactured by Facnor, as Facnor manufactures a behind the mast furling system.

However, if it is a Facnor product, we are not in position to confirm it at the moment.

We would need to contact Facnor France to have confirmation.

The factory in France is currently close for summer holidays.



Please let us know if you want us to confirm in September, when the factory will re-open."

 

Facnorrible

At the risk of getting censored for gutter coloquialisms

It might be one of the other companies in the Fac group.

Fac-tapp
or
Fac-all-use

Either way, you'll be much Fac napier with it off the mast and on craigslist