Radar Mount

[phorvati]

I received yesterday the seaview mast radar mount. The problem is that it came with rivets and one needs a rivet gun to install the thing. I was also reading in some of my literature on rigging that rivets are a pain to remove. So, should I rent a rivet gun or pay boat yard to install the mount using rivets, or should I just drill and tap into aluminum mast fine thread machine screws to hold the radar mast mount?

Sincerely,

Petar

[DeepFrz]

Petar, if you do drill and tap, don't use fine thread because it doesn't give enough of a bite. Jim Hancock wrote a fine article in the April 2006 Sail Magazine and he recommends using UNC thread and 304 grade stainless for the screws.

The article is well worth reading before you hack into your mast.

hth,
Deep

[Sandero]

You can get a rivet kit for a few bucks at home despot. Get the correct rivets... you don't want corrosion. Remove them... just drill them out.

[phorvati]

DeepFrz, does the article talk about tapping into stainless. Like tubing. I built my bimini and dodger (which are pretty stirdy) tapping 1/4-28 thread into 1" stainless tubing. Should I have gone with 1/4-20 to be more sturdy? Also the windgenerator pole is aluminum and all instructions I had were for fine thread stuff??? I whish all the boating people would get together and decide for one thing and follow that one agreement. But no, they all have to have their own way and now I am thinking I screwed up with my bimini and dodger frames.

defjef, i already have rivets. They appear to be aluminum. Are you saying that the rivets I have are not correct and I should get new ones with the gun from home depot? I'll just bring the rivet to home depot and see that I get the gun that can handle mine.

Anyway, thanks guys,
Petar

[Strygaldwir]

I'd be concerned about using bolts. The problem is the bolts, which are normally steel, will tend to weld onto the treads of the mast (see galvanic corrosion). You run a good chance of snapping them off when you try to remove them. Then, you'll be faced with trying to drill them out (an Easy-out, MIGHT work, but if it breaks, you are in deep.... water).

Easier to just buy a riveting tool and use aluminum rivets. Much better.

[Talbot]

No not aluminium rivets please unless they are totally non-load bearing. The type you should be using is called "monel" You are very unlikely to find these in any hardware store, but possibly in a swindlery. I tend to purchase whenever I am at a rigging store. This is the standard type of rivet for putting load bearing items onto the mast. Normally the large rivets of this type need the added strength of a scissor type rivet gun


Another source of monel rivets is an aircraft maintenance facility.

[DeepFrz]

Petar, I think you should be okay with the stainless, it is much stronger than aluminum. Just bed your fasteners properly. I just wanted to pass on info on the article which related to 2 rebuilds on the same mast. The second rebuild was done after 10 years of use. The first rebuild was very difficult but the 2nd went much easier. Bedding material and fasteners were covered in detail.

Anyway, I doubt that you will have a major problem with finer threads so long as the fasteners are bedded properly.

Deep.

[skipperaris]

Originally Posted by Strygaldwir

I'd be concerned about using bolts. The problem is the bolts, which are normally steel, will tend to weld onto the treads of the mast (see galvanic corrosion). You run a good chance of snapping them off when you try to remove them. Then, you'll be faced with trying to drill them out (an Easy-out, MIGHT work, but if it breaks, you are in deep.... water).

Easier to just buy a riveting tool and use aluminum rivets. Much better.

I have some times wondered. If you want to screw a 6 mm screw into alu might be a good idea to first screw in a bigger countersunk one (let's say 12 mm) with a threaded hole down its middle. Then the 6 mm screw should be easy to undo. Anyone ever tried this?

[Maine Sail]

The mount came with the rivets. A rivet gun is very inexpensive in the whole scheme of boats. I think I paid less than $30.00 at Sears for a very good quality one. I have drilled and tapped masts before and it's a lot more work than drilling and riveting. Rivets drill out very easily with a slow speed and a good bit..

[skipperaris]

Originally Posted by Acoustic

The mount came with the rivets. A rivet gun is very inexpensive in the whole scheme of boats. I think I paid less than $30.00 at Sears for a very good quality one. I have drilled and tapped masts before and it's a lot more work than drilling and riveting. Rivets drill out very easily with a slow speed and a good bit..

Yes I agree Acoustic. Nothing wrong with rivets.
How much did this mount cost?
Is this a solid mounting base or is it self levelling?

How do you pass the cable by the way? Will you cut it?

[Maine Sail]

Not a self leveling. I had a Questus self leveling unit on my last boat but due to it's back stay location, and the height of the radome, I lost performance compared to a mast mount so I went back to a mast mount. I can't remember what I paid but it was around $150.00US. I purchased it from BrokenLegDave's marine. Running the wire was easy and I did use a wire snake. The cable is cut at the base of the mast and was put back together with a Molex connector from Radio Shack the wrapped in 3M Super 33 electrical tape for water tight/moisture resistance.

[GordMay]

Although a good general purpose Vinyl tape, 3M #Super 33+ (#Super 88+ is better) is not recommended for “waterproofing” applications (except, perhaps, as a mechanical overwrap)
“Waterproofing” should be performed with Linerless Rubber* or Self-Fusing Silicone** Rubber Tape(s), or better yet, Adhesive-lined Heat Shrink Tubing***.
Ie: * 3M #130C, or ** 3M #70 HDT, or *** 3M #EPS-400 (or EPS-200) Tubing, or equal(s)

[Dunkers]

Acoustic,

Just like to say thanks for posting a fabulous photograph. I can imagine sitting in the cockpit with my wife, having a sundowner and watching the world go by with some gentle classical music in the background and good smells coming up from the galley - bliss.

Thanks for the mental imagery on a winter's day at work

[skipperaris]

Thank you Acoustic.
Also beautiful picture of a beautiful boat.

[Maine Sail]

I understand Super 33 is not waterproof but it certainly prevented any moisture from the bilge from corroding the connection. I obviously can't use a mechanical shrink wrap over a 12 pin molex connector because 1) I need to get it apart to take the mast down and 2) the iregular shape would prevent any shrink wrap from both fitting over the connector and also shrinking around the wire. With the amount of Super 33 I wrapped around it NO minsture go in!! Maybe I'll check out the 88 version. I've tried the supposed waterproof stuff but in a constant damp environment it tends to come un-done and loosens up.. Perhaps I'm not getting a good quality tape..?

Here's some more pictures for you guys:Maine Sailing's Photo Galleries at pbase.com