2452 cierra express hardtop - mounting a radar dome-gctid374484

[Guest]

Does anyone have a diagram of the 2452 cierra express hardtop? I want to drill a 1.25 inch hole to pass radar cables through, and then run the wires through the spaces under the trim in the front of the cockpit top. Do I have to remove the headliner first? (how) There seems to be a bulge around where the anchor light comes through the top, and it feels like there may be a "box" that I could drill into without hitting the headliner with my hole saw.

Installing on a Seaview 10 inch pedestal. Also, does anyone have experience with "weld mount" fasteners? I am thinking I can avoid drilling bolt holes to mount the seaview pedestal.

[TerryW]

What year please?

[Guest]

Thanks for the reply. It's a 1999 model.

[Go Aweigh2452]

danro wrote:
Does anyone have a diagram of the 2452 cierra express hardtop? I want to drill a 1.25 inch hole to pass radar cables through, and then run the wires through the spaces under the trim in the front of the cockpit top. Do I have to remove the headliner first? (how) There seems to be a bulge around where the anchor light comes through the top, and it feels like there may be a "box" that I could drill into without hitting the headliner with my hole saw.

Installing on a Seaview 10 inch pedestal. Also, does anyone have experience with "weld mount" fasteners? I am thinking I can avoid drilling bolt holes to mount the seaview pedestal.

You need to remove the headliner. First thing is to remove the upper forward cushioned planks above your head so you can lay cables down there to the helm side and to the dash. I did a RayMarine radar install on my 1996 and did what I am telling you... see photos below also. Once the planks above your head are removed, you can use a thin putty knife to pull the cushion ceiling material past the center part of where you will drill the holes for the radar. Once you have run your cables forward along the roof line and after checking that the radar is working, you can spray the back of the head liner and the underside of the cockpit with 3M 77 adhesive spray. let it tack for 30 seconds and press forward from the back to the front to eliminate any sags or air bubbles.

http://rides.webshots.com/album/502720393FWIFKS

[Guest]

Sweet. That is fantastic information Doug, and the pictures sure helped me visualize what you are recommending. I'll post back some pics of the project when I'm done!

[Guest]

The instructions and illustrations were just what I needed to get confident to drill that first hole in the roof. After that it was all downhill and a couple of days of itchy arms. Here are some project pictures.

I didn't need to peel back the headliner - I split the seam and ran wires forward to the wiring space under the headboard trim. I used weldmount fasteners on the top-side to secure the pedestal - they have 500lb strength each - so that's a ton of holding power. I still may add 4 more and anchor to the bolts under the radome jsut to be safe.

Attached files [img]/media/kunena/attachments/vb/680539=27146-dome.JPG[/img] [img]/media/kunena/attachments/vb/680539=27147-finished.JPG[/img] [img]/media/kunena/attachments/vb/680539=27148-headliner.JPG[/img] [img]/media/kunena/attachments/vb/680539=27149-routing wires.JPG[/img] [img]/media/kunena/attachments/vb/680539=27150-side panel.JPG[/img]

[Go Aweigh2452]

Nice job. Now go to your nearest Lowes or Home Depot and buy a couple of feet of wire channel with a peel back sticky side. I bought black to blend in with the black trim. Then just fold the wires in the channeling... It will look great and easy to get to as well.

Hopefully, you also left a fish line to be able to run more wire for other stuff you may want to hang off the top above the helm... I ran flat separate color four wire and it has come in handy and I only have two of those four runs available for more stuff.

Plus be sure to mark the wires for what they are for... Radar power, negative, etc. You'll be a COF someday and may forget what wire is what...

[Guest]

Thanks. Good idea on the labelling of the wires. I ran two circuits through as spares - one for an anchor light, and one for a hailer/fog-horn.

For the channel, I took a spare piece of teak that I had laying around and routed it so I have a nautical looking wire channel that won't be effected by the sea air- forgot to take a pic of that, but it came out nice.

[Guest]

Did you guys use a backing plate on the ceiling where you bolted the radar? When you reattached the fur ceiling liner, did you glue it on top of the bolts?

[Guest]

In my case, I did not. I used weldmount bolts for the 10" radar tower that I used. I am contemplating revisiting that decision (I get 2000lb staying power with the weld-mounts). Since there are bolts below the radar at the top of the tower, I am thinking of 4 more weld-mounts spreading the load top and bottom, and giving me two tons of holding power. It will help with the roof flex as well by spreading the torque over more than the current 7x7 base size.

I wish I could remember how to figure out how much force each bolt will be subjected to with a weight of 15 lbs with a center about 1 foot above my hardtop in a rocking motion situation.

The bolts that I used (weld-mount) have round flat heads which are about an inch and a half in diameter, so they get glued to the top with an acrylic resin. When bonded right, each bolt can take 500lb before the bonding gives up.

Pushing on the radar, the roof does deform some as I push side to side with a decent heave. I wanted to see if they easily broke free. I can eliminate the deformation by adding 4 more bolts out under the heads that attach to the radar (larger diameter from center) so that there will be 8 bolts spreading the weight. I just have to fashion tensioners (think threaded rods, turnbuckles) much like you see on the stays that hold up a mast.

[Go Aweigh2452]

If I recall, the top is only about 1/4" thick. I added a piece of marine ply under the top to give it more strength. Does not matter what strength the bolts are if the top will crack or split with the jiggling weight of hitting hard surf while underway. Best to have a 12x12 or bigger piece of plywood footprint under all that stress so the wood and not the fiberglass absorbs some of it... Does not have to be thick either. I think mine was 1/4" ply which was enough. I also did not have a stanchion. I bolted the radar directly to the top. Your configuration may mean more possible stress due to the height?

Of course, I always seem to over engineer stuff so maybe your OK anyway just the way it is. Maybe make a few runs to determine if there are any stress cracks afterward?

[Guest]

I like the idea of a base plate to spread the stress, for sure.

Where I drilled through, it was a good inch thick (wood core), but that doesn't guarantee the whole top is that thick.

The first thing I want to avoid is having it pop off and pitch into the drink or smash down through the front window. That's why I want to spread the torque a bit more by essentially guying it down. This will have the added benefit of spreading the load under stress.

For how you have mounted, I can't imagine there is any torque, as you say, because no height. I just did a rough calculation, and it should be able to manage a side to side of 16 MPH before getting to my lack of comfort zone with only the two bolts on any given side doing the stress relief. That's not enough margin of safety in my book, since a big wave can pitch me around like a cork. Have to rethink my strength equations and cancel some of that torque. Guying it out will help (eliminating the torque due to the 15.8 lb head being essentially 1 foot above the roof.

In a pinch I can walk, crawl or sit on my top without any stress cracks (so far anyway) - but guying it out on the 12 inch center versus the 7 inch center (and having both) will go a long way to spread the load.

[Guest]

Update - I've got to redo the mounting. I went out this weekend on an extended run, and the new radar worked great (fog, rain). On the way home, last mile to the marina, went across a big wake on plane. The mount came free, and the gelcoat was stripped right off of the glass (the acrylic glue held like a champ).

Before I left, I took chord and lashed the top of the radar mount in 4 directions to relieve stress. This saved my bacon as the dome just leaned back and rested on the back of the radar mount pedestal (did not hit the edge of the dome). The slack in the wires was just enough to make up the travel distance, luckily.

Faulty installer

Next!

[Go Aweigh2452]

Glad it was not more serious... Just dump the stanchion... The radar is fine on the top anyway. Mine is good for 48 miles (4KW, not by height) but I keep the range to about 1/2-1 mile all the time anyway... The 4KW helps in resolution at close ranges...