Radar Arch Location

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LK

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Trying to decide on the location of a radar arch on a 25.

Most Cdory's have the radar arch located aft on the cabin roof.

Why not have the arch located forward on the cabin roof ? Seems less possibility of damage to the transducers (radar dome, gps antenna, vhf antenna, etc) from activity in the cockpit.

The radar arch was part of the promotional give-away for buying a new boat. Getting an arch height of 17" in lieu of the rod holders. Will be storing an inflated inflatable under the arch.

LK
 
I have my radar arch in the back so i can put rod holders and nett holders on it. unless you are planning to take a hammer to the radar dish i don't see how having it in the back will get it hurt. I also have my gps and vhf ant. mounted there and I am able to reach up and lower them from the aft deck and do not have to walk forward to do it. a lot easier and safer.
 
I am ready to install my new Radar Arch. What product should I use to seal the plates and screw holes to avoid any water entry?
 
Kirby - all holes I have drilled in two different boats, most recently a 3-3/4" hole and 6 little screw holes in the cabin roof for the solar vent, have been sealed/caulked with 3M 5200. This is a great combination adhesive / caulking,

C-Sick":2fi9e281 said:
I am ready to install my new Radar Arch. What product should I use to seal the plates and screw holes to avoid any water entry?
Click to expand...
 
C-Sick":23k21ql2 said:
I am ready to install my new Radar Arch. What product should I use to seal the plates and screw holes to avoid any water entry?
Click to expand...

I agree with Pat that 5200 is the way to go. Also, you might want to consider installing the radar arch with through holes and bolts (with steel backing or fender type washers on the inside) as opposed to screws. I think that's what the factory and most other people do. You want to be sure it's well mounted and can be used as a handhold without worry. Also, if you mount a bunch of other stuff on it (antennae, rocket lauchers, fender hangers, inflatable ties downs, etc), it can be subject to a fair amount of stress/torque.

Roger on the SeaDNA
 
Pat, Roger

Thanks for the feedback. I plan to bolt through with backing plates.

Any tricks to working with 5200. Is there any margin of error if you get it on part of the gel coat where you don 't want it etc.

I am so excited aboutl having the arch. Unfortuately being a poor man I am going with the 1623 Furuno Radar but heck it is radar just not sexy.
 
I am going out to buy the hardware on Saturday. Anybody know what size bolt and style of nut to use.

I am planning on using as SS Hex (don't know for sure length) with nylon washers, and nylon nut.

Anybody know exact bolt diminsions?
 
C-Sick":33ido9ik said:
Pat, Roger

Thanks for the feedback. I plan to bolt through with backing plates.

Any tricks to working with 5200. Is there any margin of error if you get it on part of the gel coat where you don 't want it etc.

I am so excited aboutl having the arch. Unfortuately being a poor man I am going with the 1623 Furuno Radar but heck it is radar just not sexy.
Click to expand...

I cleans off pretty well with a rag. However, like most caulk/glue products, I find the more I mess with it, the less attractive the final outcome. Usually I just squeeze a blob in the hole and coat the threads on the bolt/screw, and, depending on hole size maybe put a dollop under the head of the bolt and nut. The excess gets forced out into a relatively symmetrical bead on tightening - especially if you don't have a vast excess. As soon as I decide to "clean it up", I wind up spending a lot of time getting back to something that doesn't look as good as the starting point. Others may be better than I at this, but that's my experience.

I'd probably use the same size bolts as are used for the hand rails - I think those are 3/8 diameter but am not sure. Why don't you do a quick call to the factory to see what they use? They can probably rattle off the right diameter and length in an instant. Every time I have called about something similar (which I have only done a few times), I got good info in 10 mins or less. I'm not so sure about the nylon nuts for this application. Nylon nuts are good for relatively low torque applications but you might want stainless for this.
 
I agonized long and hard about this. Visited my new boat in Seattle at the facory yesterday and took her for a short shakedown. I'm happy with the decision I made to position it aft, and to go for the lower model. It looks great and is very functional. In my case I hardly ever carry an inflated dingy, so the higher arch was not necessary. The lower version comes with 4 rod holders, providing storage for nets, rods, etc.. It is very sturdy and a first class installation.

Recommendation: The thru bolts don't need more than large washers as there is very little stress on it, but the bolts should be capped with acorn nuts as they are just overhead on the port side.

Mike - Sealife
 
I picked up the 3M 5200 fast drying caulk today. I am going to have to drill the first pilot hole to determine what size SS bolts I will need. I plan to use SS backing plate and SS acorn locking nuts with the nylon threads and nylon washers.

YIKES

Any other suggestions before I take the fiberglass plunge?
 
Here's a little tip for using that 3M 5200. Acetone cuts it really well before it is completely cured. It's great for clean up, and it won't hurt the gelcoat. If you want a bead around whatever you're attaching, you can wet your fingertip with acetone, and use your finger to shape and contour the exposed caulk. (Don't let Rogerbum see you put acetone on your bare skin - he's a biologist or something.) If you need just a little of the stuff, you can swipe your wife's fingernail polish remover. A little bit on a rag does a lot of clean up if you wipe the big stuff off first.

There have been lots of good ideas posted to keep from chipping the gelcoat when drilling the fiberglass. Masking tape seems to be real popular. I use a coutersink bit to either drill the hole thru or cut away the gelcoat to a little larger diameter than the finished hole will be. If you just stick a sharp drill thru the glass without thinking about it, you will get some ugly chips in the pretty surface. YIKES is right!

Have fun!

Mike
 
Quick tip #1 when working with 3M 5200, have several paper towels and a can of WD-40. Works great for cleaning exess stuff from around the sealed area and from your hands as well.

Just be careful not to get it under the seal or you wont have a seal, WD-40 dissolves uncured 5200 with ease. :D
 
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