Radar Arch Nuts Loose

[feeez]

The radar arch attachment nuts and lock washers on our 350 Mariner are located behind 4 access panels on the arch. I recently decided to replace the plastic screws that hold the panels in place with stainless as some of the heads had broken off.

After removing the panels I noticed that 2 of the 4 nuts were loose to the point that the lock washer was no longer compressed. One of them I could move by hand.

Just thought I would pass this along.

Cheers
Fraser

[daveS]

Thanks Feeez
I will check mine

[mjk1040]

Just did the same thing on our 355! Everyone needed to be tightened. What size and type of SS machine bolts did u replace the plastic one with? I replaced the broken ones with new plastic ones, but now wish I went to SS ones.

[feeez]

Qr Bbpost Just did the same thing on our 355! Everyone needed to be tightened. What size and type of SS machine bolts did u replace the plastic one with? I replaced the broken ones with new plastic ones, but now wish I went to SS ones.

I believe the appropriate replacement was 10-24/ 3/4" SS machine screw.

Cheers
Fraser

[nightsky]

Thanks for the heads up. I was in behind that access panel recently to run wires from a solar panel I installed on the hard top. Saw those bolts but didn't think to check them. I will do so. On the issue of SS nuts and bolts for the access panel, mine has them, but I found that the stainless reacts with the aluminum of the panel and the arch and several of the threads on the aluminum corroded away. Perhaps the plastic is a better choice just for this reason.

[Viper]

Qr Bbpost....On the issue of SS nuts and bolts for the access panel, mine has them, but I found that the stainless reacts with the aluminum of the panel and the arch and several of the threads on the aluminum corroded away. Perhaps the plastic is a better choice just for this reason.

BINGO! that's why they use plastic. You can use stainless steel but you must take measures to prevent galvanic corrosion. I use Tef-Gel on the threads when fastening dissimilar metals.
http://www.tefgel.com/contain.php?param=tefgel_price

[mjk1040]

Ah! Ha! That solves the $60K question why they used plastic in the first place.

[bud37]

So Fraser, I finally got tired of looking at the missing screws on ours , thanks you are responsible here .......well they were a mix of plastic with heads, headless and SS with the heads painted white, the SS were all fine but the plastic I replaced with stainless and will paint them white next year...the bolt was fine....interesting as there is no gasket here and you can see some evidence of small amounts on moisture getting in there, so I caulked the seam with some simple caulk and I think I will make gaskets next year to seal them and make removal easy......it is possible there could be another reason for the plastic perhaps....cost......

[feeez]

Qr Bbpost interesting as there is no gasket here and you can see some evidence of small amounts on moisture getting in there, so I caulked the seam with some simple caulk and I think I will make gaskets next year to seal them and make removal easy......it is possible there could be another reason for the plastic perhaps....cost......

I had the same feeling about that when I put them back together. There was a real build up of green yuck between the plates and the arch so rain water it making its way in there for sure.

Fraser