Old Top Section ----> New Boom

rock steady

New Member
I'm wanting to make a new boom out of a snapped top section. Can anyone help with tips?

Should I use stainless or monel alloy rivets? What about through bolting the outhaul fair lead and mainsheet block?

thanks,

Chris

:) :) :) :) :) :) :)
 
1. get the reinforcing tube and install it
2. Do NOT through bolt all the way throiugh and out the top.

re stated...it is great for life expectancy to use a nut / bolt arrangement instead of rivets for any attachment. drill through the pipe once. Do not drill through pipe, air and more pipe. Pulling down on the top of the boom with the mainsheet block will dent and break the boolm. Pull on the bottom of the boom with the end of the fastener on the inside of the bottom.

Attach the mid boom block by reaching to the middle of the boom with a long stick and extra long bolts taped on. Push the bolts out through the holes...Then hold that excess length while you tighten the nuts, then cut off the excess and make the stubbs smooth so they will not cut you.

Back of the boom?? fasten the clew fitting just to the top and the mainsheet eyestrap onlyto the bottom. Don't crush the boom!!
 
Chris, if using rivets, you should use monel type since they are less galvanic corrosive to the alu.tube. On the other hand, the vang steel plate is the biggest problem here anyway.

I use bolts (M4 machine tread, 4,0 diam.) in A4 quality (stainless steel/acidproof) and M4 nuts with nylon locker.
Follow gouvernails advice/description how to mount and get the measures/positions correct.

Suppose you have an old boom - take care of the inner reinforcing tube and reuse it. Otherwise I dont know how to be "class legal". Its a simple alu. tube with outer diameter of 45mm. The length can be up to 900mm according to the class rules (mine was 600mm). The inner tube center is aligned to the vang plate.
This dimension can be bought from any supplier of aluminium goods/profiles, but I dont know if its ok in the eyes of an measurer - anyone comment on this?

Regards
Magnus
 
Thanks for the feedback guys, much appreciated.

In terms of getting measurment correct, the boom length seems to be from end plug to end plug - so do I have to cut the length 10mm shorter to meet specifications?

Also - what size rivets do you reccomend?

thanks again
 
Hi,
The rivets are 4,8 mm diameter, but I'm not sure about the length(s). The length is depending on the item you are mounting. Believe its 12mm length for vang plate and block lacing eyes, maybe ok for end plugs and cleat too.
For the fairlead you need quite longer, maybe 16mm is ok.
NOTE: Important you drill the holes with exact 4,8mm drill. Do not use 5,0mm! And use a good rivet tool too.

Or go for the bolts - its in fact easier (and much more reliable) if you first need to find the 4,8 drill or a rivet tool.
Good luck!
/Magnus
 

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