Hi, ive got a Gaastra alloy vgrip 200-250 boom.New sail needs 257. Only leaves 10cm sleeved if i were to drill hole at 257. Feels a bit floppy for my liking. Id like to get some tube n bend to make new tailpiece.
1. Would it be ok to just drill the original?
2. Anyone know what GRADE alloy id need to make a longer tailpiece?
Thanks Crew 
There are problems.
Stiff Alloy tube doesn't like to bend. It also needs to be anodised or it will corrode very quickly. I would think manufacturers would use soft alloy tube to bend it , then heat treat then anodise.
A solution could be to make an extension for your extension.
Get some tube ( 200 mm ) the same diameter as the boom extension , could be plastic.
Then join the tube and extension with good quality wood dowl on the inside of both ( 200 mm each way ). Glue in both sides.
I would think hardwood dowl would be strong enough but something else could be better. ( alloy tube ) ???
Imax1 ive seen a carbon diy tailpiece article on seabreeze. Made of balsa n carbon etc.2 tubes with a plate of balsa between to support sheaves n cleat.Could i substitute a 200mm x 50mm x 3mm (roughly)alloy plate to support sheaves n weld or bolt plate into slotted tube ends? Im only extending from 250 to 265cm or so.
Sweet looking job this one 
NEVER add holes to the boom extensions or the base extensions for your mast. The holes stop where they stop for a reason, it leaves the minimum amount of tubing needed inside for the required strength to prevent parts failure.
New longer rear ends can be bought if the boom isn't ancient, or just look for a used longer boom.
Making an extension for your extension is also a poor idea, you end up with the main boom body being too short to accommodate the lengthened extensions, leaving you with a super flexible boom which could also fail due to its flexing.
Just look for a longer boom, do it the right way.
I think the bottom line is ,Mastbender is right otherwise it could be a dodgy fix.
Extending the pully end is totally possible with a carbon boom if you know what your doing but not with an alloy boom unless you really know your alloy welding.
I would think breaking a boom while sailing is not very much fun.
Personally i also would look for a rough looking ( cheap ) second hand boom and re grip it. A early Christmas present to yourself , thats what i say to me . 
So rather than extend. Id like to make a completely new tailpiece similar to the pictured carbon one. But in alloy. Source alloy tubes, cut at new desired length. Cut alloy plate to mount sheaves. Slot one end of each tube to suit plate. Weld or bolt plate to tubes. Bolt sheaves to plate. Drill holes in tubes at desired length to suit sail dimension. Any alloy boatbuilder could weld it together cheaply n easily. Any other fabrication is diy.
Whatcha reckon?
Once you weld you lose the temper. It obviously needs to be tempered so it does not fold like ally used in say a TV aerial
Just find longer tubes with a near enough correct angle on back end, to use for just that one sail. They won't go all the way in for small sails , but that is when u use the factory tubes. It is usually the other parts that break, back ends abound.
I would not do that for too much length but for 7cm it should be no issue.
Hi Olskool,
Are you you going to use the boom with other/smaller sails?
I have a boom extender in carbon (but should stilll work in alloy), where the original tail piece tube was cut in half & a sleeve, the same size as the boom arms, was glued onto/over the 2 original halves of the tailpiece tubes, extending the boom for 15cm (or what ever length you need)
You do loose some of the range of extension though
could be a cheap option if if you can get some old broken boom arms that suit
Boom is 200-250. I need it to be >260ish. Have no sails less than 210. Local shop just chucked all their old tailpieces away. 
Probably didnt have it anyway.Gaastra vgrip tailpiece is quite small diameter. 25mm or less.
Geoffo so instead of adding to the tailpiece ends. Cut n add closer to boom sheaves end? (ie in the middle)
Hi Olskool,
Something like like this is what I think has been done, I will take a picture of my tail piece extension when I get back to Sydney on the weekend.
Though this might not work for you as you want the smaller extension range
If you insist on using alloy for a big boom then consider getting some T6 Tube that will fit neatly over the grip of the original boom.
Larger diameter will give you much more stiffness.
North Sails do it with their Carbon Booms.
Techno used to do it with their Ergal Booms as well.
Use an old back end cut off to about 100mm and sleeve it to suit the bigger tube.
Cut the clips off the boom arms & use internal push pin adjustment.
I was planning the same thing with one of my carbon booms but ended up buying a new boom.
In the olden days before carbon booms were so affordable Hydrodynamix had a big alloy race boom which had and extension 28mm dia x 1200mm long and 2mm thick, most stayed inside the arm for stiffness though with 500 adjustment.
The other cheap & easy option is to get your sail modified with a cut-out at the clew, if it doesn't already have it.
I have drilled extra holes in an old arrows boom long ago to get over 250, it was quite noodly but didn't break.
As far as Gaastra v-grip goes, it's unlikely to bend or break the tail piece. Exhibit A:
Select to expand quoteNinjury said..
I have drilled extra holes in an old arrows boom long ago to get over 250, it was quite noodly but didn't break.
As far as Gaastra v-grip goes, it's unlikely to bend or break the tail piece. Exhibit A:
Ba Boom! Exhibit A: mine doesnt look quite like that. 
Select to expand quoteNinjury said..
I have drilled extra holes in an old arrows boom long ago to get over 250, it was quite noodly but didn't break.
As far as Gaastra v-grip goes, it's unlikely to bend or break the tail piece. Exhibit A:
Nice photo Ninjury.
Some booms are so sexy no matter how bent they are, this one was a 1972 Cleo centrefold
^^^
I love my windsurf gear also,
but,
sexy boom poses with flowers could be a sign of a bigger problem.
Select to expand quoteImax1 said..
^^^
I love my windsurf gear also,
but,
sexy boom poses with flowers could be a sign of a bigger problem.
Ya reckon??? Looks like its already on the lounge. Ready for questioning. CLEO you say.???........
Inverloch ?
