Rigid Vang Installation: Tap and screw, or rivet?

[Scup]

I have a Spinlock Powervang VX that I will be installing on my S2 27. The installation instructions call for installation of the mast and boom brackets by drilling holes, tapping, and screwing. Anyone see a downside with using SS rivets instead? Thanks for the input.

 

[shorty]

I tapped

when installing Garhauer rigid vang. Pretty easy operation. Are the rivets truly SS? Aluminum rivets certainly would not have the strength of bolts. I'm not real savvy on rivets.

 

[Ross]

Dave, there is no down side to drilling and tapping!

If you need to take it apart you need a screw driver. If you rivet it and need to take it apart you need a drill.

 

[Joe]

tap and bolt.....

definitely. Stainless rivets are almost impossible to drill out withough damaging aluminum spar. When you attach bracket put a layer of plastic electical tape on the inside to insulate it from the aluminum spar, then coat the fasteners with anti corrosive gel. Another suggestion is to get all the fasteners loosely attached before trying to tighten down. That way you can jiggle the bracket into place if the holes are a little off.

 

[Dick Westwood]

Rivets

As I mentioned in another post:I have a Garhauer rigid vang. It's attached to the mast with stainless self tapping screws. But it's attached to the boom with aluminum rivets.I used rivets at the boom because the aluminum in the spar is really thin, and (my first attempt at) self tappers didn't seem to provide enough "bite" - not enough turns of the screw for me to feel confident.The aluminum rivets work just great. They've been in three seasons, with no problems. I thought they might not be strong enough, but they definitely are. The rivet gun was pretty cheap, the work was easy, and the result was great.By the way: to deal with corrosion, I back the stainless steel vang attachments with a cutout from a plastic milk bottle. Pretty easy to do. And I use locktite to deal with the stainless-aluminum points of contact.

 

[Timo42]

Why would you have to

buck a blind fastener? If the rivet is set properly it shouldn't work harden, even if it's aluminum. I have been using 1/4" aluminum rivets in automotive power window regulators for 20 years, rarely have I seen a failure in the rivet, otoh every repair attempt with nuts and bolts that I have seen has come loose. This is a high shear repetitive strain on thin sheetmetal parts. I looked at a table last night and the cherrymax are stronger, but the aluminum substrate would fail before either type of rivet. I practise what I preach, my main sail halyard block is held on with rivets. Tim

 

[John S]

Timo

TimoI have been setting rivets and nut bolt combinations in aircraft for 30 years. You are right about nuts and bolts eventually coming loose. My point, which I did not phrase elegantly enough, is that you can work harden solid SS rivets while bucking them, and they will fail to expand and become upset properly. Also, setting your 1/4 inch aluminum rivets will require bucking unless they are blind, in which case are you recommending HOLLOW rivets for installation of this highly loaded device?The great thing about solid aluminum rivets is that their metal and that of the boom or mast, are nearly alike. Hollow rivets have very little shear stregth. Cherry Max rivets are expensive (at least $.25 each in quantity). Cherry Max rivets do have some non-aluminum parts in the stem lock. Properly set, they have the benefit of the strength of a nut/bolt with the blind setting capability of a "pop" rivet. That's all, set what you want. John S

 

[Timo42]

John S

The rivets I am using for the masthead sheave and other places are sealed at the end, the mandrel is retained so in effect you have a solid rivet. I agree about the Cherry max rivets, and any rivet in that strength range won't be cheap, I am NOT *yks recommending hardware store or harbor freight rivets. I think we all want to keep the bright shiny bits attached to the boat. Tim

 

[John S]

Solid Blind Rivets?

Please tell the brand name and source for the rivets that you use. Properly set, a solid aluminum body blind rivet would be a very good solution. by the way, I have seen many mast and boom attachments made with large hollow rivets but I have no data on their longevity, except to say that every one I have inspected has corrosion, even though they appear to be aluminum.

 

[Timo42]

I will see if I can get a #

I have been getting them as part of a door lock actuator kit at work, they are rounded at the end and the end of the mandrel stays inside the rivet, I may be able to find a picture tonight. Tim

 

[Paul Brinkley]

Don't have a supplier or number, but they are used

in the truck body industry, as well. They are watertight, which most hollow pop rivets are not. I'm sure most industrial fastener suppliers could get them for you. -Paul

 

[Ross]

Go to Mc Master-Carr and search sealing

blind rivets. They have them.