What's the best way to install a clam cleat on the boom of my Ty? I tried SS sheet metal screws, but gave up after the second one sheared off. My next thought was to just tap the holes and use SS machine screws, but am a bit concerned about the strength of tapped aluminum. Would pop-rivets or bolts with nuts be better? I'd prefer not to use pop-rivets because I'd have to buy yet another tool (and I'm unsure about the strength of pop-rivets), and I'd prefer not to use bolts with nuts because the screws affixing the boom end-cap are frozen and don't want to budge. But if machine screws won't work, I'll do what I need to do.
This cleat is for a reefing system (I know, a horn cleat would be better than a clam cleat for this application, but the clam-cleat is what I have on hand).
TIA,
ED
ed.armstrong@innercite.com
installing cleat on Ty boom
Moderator: Jim Walsh
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Don Carr
Re: installing cleat on Ty boom
Go with the tapped hole and machine screws.. The cleat will be working
a lateral force and should not be a problem strength wise.
IMHO
carrds@us.ibm.com
a lateral force and should not be a problem strength wise.
IMHO
carrds@us.ibm.com
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Bill Bloxham
Re: installing cleat on Ty boom
Ditto that.
I use a thread locking compound for corrosion protection from the stainless in the aluminium thing.
mmmmmmbill@earthlink.net
I use a thread locking compound for corrosion protection from the stainless in the aluminium thing.
mmmmmmbill@earthlink.net
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Ed Armstrong
thanks. this board is a great source of information!
I should've asked this question before I tried the sheet metal screws. It would've saved me an hours worth of work trying to extract the screws when they sheared (worked with the first), and cutting and drilling the second out (which didn't work so well, and I'm sure will be a source of galvanic corrosion in the future.
ed.armstrong@innercite.com
ed.armstrong@innercite.com
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JimL
Re: installing cleat on Ty boom
When you're absolutely, positively stuck with SS sheet metal screw....
I have good hard steel screws to match my box of assorted "onboard emergency" SS screws. I keep them in a little oiled container. Drill the hole, then screw in the steel screw to "make" the threads, and pull it back out. When you install the SS screw you'll have a good feel for actual tightness and won't break off trying to size the hole.
I've had good luck using this method because it will compress aluminum around the edge of the hole, providing a strong grip for the SS screw. Drilled and tapped holes are great unless the screw gets a chance to work.....in which case you're better off with the sheet metal screw (that comment ought to bring some howls). Here's a story:
On our modern race engines (converted from current production stuff), we install studs to bolt the heads onto the blocks. Because the blocks are thinner and "not as tough" as the old stuff, we drop a ball bearing in the hole, then slightly overtorque the stud into the block to "jam up" metal (in the deck area). This hardening effect gives better bite with less distortion in the bores. Now we can use nuts on the studs and they'll hold more pressure than exactly the same size bolt threaded into the block....think about it! Pretty similar to what happens when you force aluminum to compress out to a screw bore size.
There is also a gadget called "nutsert" that puts an aluminum ferrule into a larger hole. The insert has it's own threads (available in a variety of sizes). The tool sets the insert very firmly in the aluminum, and keeps a full set of threads for your mounting screw/bolt. These things do NOT like curved surfaces, but are very strong when fully set. They work on the principle of a very large rivet, that happens to use a bolt in the middle (you can take things on and off). They are commonly used for roof-rack installations on modern SUVs(too many lawsuits if roof-racks full of luggage fall off the car.....we actually had a customer who claimed she lost two large suitcases full of gold bars, because her roof-rack came loose!)
A tip about drilling holes in thin aluminum. Whenever possible, use "step bits" which have all the sizes starting from small to 1/2" on the bit. Step bits, by their design, drill perfectly round holes and MUST be used with nutserts (regular drill bits make a three-sided hole, when drilling with hand held tools). Once you've tried a step bit, you'll be a believer. Also....they'll drill both directions, in case you dull an edge. (note: They make the prettiest round holes in thin fiberglass you've ever seen!)
Hope this gives some food for thought.
Regards, JimL
leinfam@earthlink.net
I have good hard steel screws to match my box of assorted "onboard emergency" SS screws. I keep them in a little oiled container. Drill the hole, then screw in the steel screw to "make" the threads, and pull it back out. When you install the SS screw you'll have a good feel for actual tightness and won't break off trying to size the hole.
I've had good luck using this method because it will compress aluminum around the edge of the hole, providing a strong grip for the SS screw. Drilled and tapped holes are great unless the screw gets a chance to work.....in which case you're better off with the sheet metal screw (that comment ought to bring some howls). Here's a story:
On our modern race engines (converted from current production stuff), we install studs to bolt the heads onto the blocks. Because the blocks are thinner and "not as tough" as the old stuff, we drop a ball bearing in the hole, then slightly overtorque the stud into the block to "jam up" metal (in the deck area). This hardening effect gives better bite with less distortion in the bores. Now we can use nuts on the studs and they'll hold more pressure than exactly the same size bolt threaded into the block....think about it! Pretty similar to what happens when you force aluminum to compress out to a screw bore size.
There is also a gadget called "nutsert" that puts an aluminum ferrule into a larger hole. The insert has it's own threads (available in a variety of sizes). The tool sets the insert very firmly in the aluminum, and keeps a full set of threads for your mounting screw/bolt. These things do NOT like curved surfaces, but are very strong when fully set. They work on the principle of a very large rivet, that happens to use a bolt in the middle (you can take things on and off). They are commonly used for roof-rack installations on modern SUVs(too many lawsuits if roof-racks full of luggage fall off the car.....we actually had a customer who claimed she lost two large suitcases full of gold bars, because her roof-rack came loose!)
A tip about drilling holes in thin aluminum. Whenever possible, use "step bits" which have all the sizes starting from small to 1/2" on the bit. Step bits, by their design, drill perfectly round holes and MUST be used with nutserts (regular drill bits make a three-sided hole, when drilling with hand held tools). Once you've tried a step bit, you'll be a believer. Also....they'll drill both directions, in case you dull an edge. (note: They make the prettiest round holes in thin fiberglass you've ever seen!)
Hope this gives some food for thought.
Regards, JimL
leinfam@earthlink.net
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Ed Armstrong
RE: thanks Jim, good information
Makes me feel better about using a big-ol' SS sheet metal screw to attach the reefing hook (or whatever that piece is called that accepts the tack of the reef) to the front of the boom.
ed.armstrong@innercite.com
ed.armstrong@innercite.com
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JimL
Be sure it is in shear, if that's how you're doing it....
I have my aft reef line dead-ended to an eye on the boom, with SS sheetmetal screws in shear (holding the eye). My forward reef is handled by an S hook on a block, with the dead end secured to the vang bail bolt and the working end to a track slide cleat below the boom. I did the front this way because I can put more pressure on the main halyard, during the operation, than I can put on the aft reefline. It also serves as my Cunningham when the main is at full hoist. Make sense?
Regards, JimL
leinfam@earthlink.net
Regards, JimL
leinfam@earthlink.net