What are these screw things called
- Thread starter bearnance
- Start date
That is a clam cleat with a fair lead. He has one similar to it for sale at defender
Thank you I know that I'm unsure how to unscrew it from the boom im not sure what I need to use
The photo is not clear but that appears to be a rivet head. If so, it must be drilled out, or ground out with a rotary tool such as a Dremel.
You can replace it again with a pop rivet. If you need to buy a rivet tool I suggest you get one with long handles. The ones that have small handles like pliers are cheaper but much more difficult to use (requiring a lot of grip strength).
The boom is aluminum, use aluminum rivets not stainless steel. The SS rivets will corrode.
A decent pop rivet kit should be part of your boats tool kit. When I was active on my Nacra beach cat, all the fittings were attached with aluminum pop rivets. Very very handy tool. Aluminum rivets are easy to remove with a drill bit. It will skim off the head of the rivet and the expanded body/shank will drop down the other side. Avoid damaging the hole by trying to extract the shank. If you've shaved off the head and the expanded body is still wedged in the hole, you can tap it lightly, or even use a nail punch, to release it.
Here's a simple pop rivet tool that should be adequate for your needs... aluminum rivets are softer that SS and you'll have little trouble operating the less expensive one. Under $20 anywhere. The one pictured is from amazon.com. But any hardware store will have a decent selection. Don't waste money on an electric model or some other fancy tool........ unless you're going into the boat repair business!
Here's a simple pop rivet tool that should be adequate for your needs... aluminum rivets are softer that SS and you'll have little trouble operating the less expensive one. Under $20 anywhere. The one pictured is from amazon.com. But any hardware store will have a decent selection. Don't waste money on an electric model or some other fancy tool........ unless you're going into the boat repair business!
Seldon and other mast manufactures recommend, use, and sell monel rivets. Most beach cats, including Hobie, use monel. Aluminum sounds good, but in fact is more prone to corrosion and much weaker (which is why it is easier). But that is only what I have observed over the past 40 years.
It look like you will need a nose extender on the rivet gun to fit in the narrow channel. Depends on the gun and the nose piece shape. A stack of nuts or washers can work.
I would not chose aluminum rivets for a highly loaded item like a clam cleat.
It look like you will need a nose extender on the rivet gun to fit in the narrow channel. Depends on the gun and the nose piece shape. A stack of nuts or washers can work.
I would not chose aluminum rivets for a highly loaded item like a clam cleat.
For a highly loaded application in a saltwater environment, aluminum would be a poor choice. However, this is on a 16' day sailer in fresh water the loads won't be very high, especially for the halyards.
Agree, but for higher strength I'd use monel rivets (not stainless steel)
I prefer monel rivets. But you'll need a serious rivet gun to put those in.
But for a small daysailer - I wouldn't worry, aluminum rivets should work
dj
If it is for a one time use, I suggest that you beg, borrow, or steal that "serious rivet gun". They can be very pricey.
PS Just kidding about the stealing part. Maybe renting is a better idea.
under $50 - do a web search on long handle rivet gunIf it is for a one time use, I suggest that you beg, borrow, or steal that "serious rivet gun". They can be very pricey.
PS Just kidding about the stealing part. Maybe renting is a better idea.
I've not had problems with stainless, but monel has always seemed a step up. My rivet gun is such that I wouldn't be able to do what you suggest above as the lower handle is what moves. If it were the other way around I suspect that's correct - as you say, a couple are OK, more than a dozen and get me a bigger rivet gun...
dj
Not completely True.
Check here for best information.
Sailboat Owner's Guide to Corrosion
Open discussion on the effects and remedies on corrosion.
forums.sailboatowners.com
Even you contributed.
Jim [aka Chemical Engineer]
Aluminum might be an ok choice from a corrosion standpoint, but it’s significantly weaker than any form of steel or monel, so not a good choice from a strength standpoint if highly loaded.
From a corrosion standpoint neither aluminum nor stainless by themselves are bad choices. The problems happen when the two meet. Stainless, being more noble, will tend to weaken any adjacent aluminum. They also tend to get stuck together, though with rivets that’s not as much of a concern as with screws or bolts.
Context is important. Any statement taken out of context can be distorted and misinterpreted.
An aluminum rivet, the kind one buys in a big box HW store, on a highly loaded application would be a poor choice relative to using Monel rivets or other ways of attaching things to an aluminum mast or boom.
Would it be appropriate to use aluminum rivets to attach a whisker pole eye to the aluminum mast on my boat? Absolutely not, the shear strength isn't there. Is an aluminum rivet adequate for a halyard cleat on a 16' boat sailed in freshwater, sure, there that doesn't need much shear strength.
Do your engineering then.
https://en.wikipedia.org/wiki/Shear_stress
Stress versus Shearing force.
Titanium for the Win !!
Jim...