Rivet size for Mast mounted Radar?

[epiic]

I am installing a Scanstrut mast mount for my B&G 4G Radar.

I have an in-mast furling main with conduit built-in for all the electronics. I have a hole where the Radar should be mounted with a messenger coming out of it so I am guessing Jeanneau does this for future radar installs.

The issue is the hole size is too small and will need to be widened. How exactly can I do that without damaging the messenger?

Thanks guys!!!!

[Cotemar]

Use a 3/8 Round Bastard, Rat Tail File.
Will be easy to make that hole any size or shape you want.

[Jim Cate]

Gotta remember to not shoot the messenger before he delivers the message. The same sorta goes in your case... you could pull the cable before attempting to enlarge the hole.

Jim

[wayne.b]

Originally Posted by epiic

I am installing a Scanstrut mast mount for my B&G 4G Radar.

I have an in-mast furling main with conduit built-in for all the electronics. I have a hole where the Radar should be mounted with a messenger coming out of it so I am guessing Jeanneau does this for future radar installs.

The issue is the hole size is too small and will need to be widened. How exactly can I do that without damaging the messenger?

===

You could use a Dremel tool with a 1/8ths inch carbide bit. Obviously you need to be careful not to ding the messenger accidentally.

[Jim Cate]

BTW, what about the rivet size that you mention in the title block?

Jim

[leftbrainstuff]

Originally Posted by epiic

I am installing a Scanstrut mast mount for my B&G 4G Radar.

I have an in-mast furling main with conduit built-in for all the electronics. I have a hole where the Radar should be mounted with a messenger coming out of it so I am guessing Jeanneau does this for future radar installs.

The issue is the hole size is too small and will need to be widened. How exactly can I do that without damaging the messenger?

Thanks guys!!!!

Put a slit plastic sleeve around the messenger or use a piece of wire pulled by the messenger through the hole.

Use a dremel and carbide bit to hog out the hole.

Fiddly up the mast but that's your lot.

You could also cut off the lower connector, pull the cable and then use a junction box to reconnect.

As for rivet size you either need many small rivets or a few large rivets. Smaller rivets (1/8") are easier to pull at height.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[roverhi]

I'd prefer drilling and tapping the fasteners rather than rivets. A short length of small diameter copper pipe over the messenger. A piece of wire with the messenger tied onto the end and the wire hooked on the hole with the messenger inside the mast is another way to prevent an uh oh!!

[GordMay]

Use a “step drill”
➥ Unibit Step Drills - Drill Bits - Tools - IRWIN TOOLS

[Cadence]

What about popping a hole just below the current one of adequate size. Pull your wire and fish it out through the larger hole. Fill the messenger hole. Just as a shot in the dark, check to see if the messenger hole may meet your needs for a mount hole. I know it is far fetched but worth a look.

[earthmover]

Lots of excellent info offered. I used to build airplanes for deHavilland in Toronto. My first day in training the instructor gave us a golden rule for drilling rivet holes, "You can drill a hole bigger, but you can not drill it smaller". This seems simple and common sense, until you drill the hole too big. Don't use a step drill. Gradually open the hole by using individual drill bits. If you want a stronger pull-thru rivet then use aviation grade. This means using aviation drill bits. There is no 1/8th in aviation rivets. The hole in that case would be finished with a #30 drill bit.

[notiesbob]

Is the mast up or down? Good if down. You likely have another wired fitting nearby like steaming/deck light. Remove fitting to slack wire, fish it out of the radar feed hole, secure radar tracer to the wire then push back into mast. Now you can drill a clear hole the size you need. When done fish tracer out. Hole a bit oversized is better than tight when it comes to getting big cable through. The whole project will be much easier with mast down if possible. 16 lb product weight plus mount weight - drill and tap is better than rivet IMHO.

[pdenton]

A step bit is by way of a DIY Saturday morning tool, certainly never for a job that requires precision. A 1 inch hole in metal! that's a job for a drill press and a number of gradually increasing bits of metal if thick and a lot of care if it's thin. It would be foolhardy to use it on the mast, where it could easily grab metal and go all the way in. If in the air, use the above-mentioned rat tail file of the "highest grit". Sheet metal is very difficult to drill properly.
pdenton

[Chili Palmer]

Originally Posted by pdenton

A step bit is by way of a DIY Saturday morning tool, certainly never for a job that requires precision. A 1 inch hole in metal! that's a job for a drill press and a number of gradually increasing bits of metal if thick and a lot of care if it's thin. It would be foolhardy to use it on the mast, where it could easily grab metal and go all the way in. If in the air, use the above-mentioned rat tail file of the "highest grit". Sheet metal is very difficult to drill properly.
pdenton

I'm not a fan of step bits either but I can say with certainty, they will not grab and go on their own, you have to apply pressure.

Would a rivnut be of any use in this situation? We used them extensively when building control panels and often wondered if they could be used on a mast.