Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1

TOPIC: 3218 arch rebuild

3218 arch rebuild 13 Aug 2012 22:29 #1

  • R&Jonthebay
  • R&Jonthebay's Avatar Topic Author
  • Offline
  • Platinum Member
  • Platinum Member
  • Posts: 1421
  • Thank you received: 60
OK….so after yet another question being posted about rot issues on 32xx and 38xx radar arches, I finally found the time to put together this thread on my arch rebuild.
I will apologize in advance because I seem to have lost some of the pictures of the process….sorry. I’ll explain it the best I can.

It’s my opinion that the rot issue is caused by a couple of factors. Inferior materials and poor construction methods are the two leading reasons.
Firstly; #2 pine was used as the blocking material. Its purpose was to add some strength to the arch and provide an anchor point for the vinyl covered panels. Western Red Cedar, Cypress or even treated lumber would have been better choices. The wood was put into the arch in short sections and glassed over.

Secondly; the white vinyl trim contributes to the rot by channeling water under and between the panel and blocking. The shape of it is somewhat that of an ”L”. It has a half round bead that wraps over the fiberglass to provide a finished look and transition to the panel. A 1” wide flat comes off it and is used to attach it to the blocking. It was attached to the blocking with SS staples. No caulking was used to prevent rain water from running behind it as it flowed down the arch. As water intruded, it hit the staples and capillary action carried it into the wood. Once the wood was wet there was no way for it to ever dry out considering that it was sealed in fiberglass and resin.

Thirdly; the vinyl wrapped, plywood finish panel also rots for the same reason. It gets wet on the back side from water intrusion at the transition and can’t dry out either.
Wood wrapped in vinyl is just a bad idea from the start, unless there’s no way it can ever get wet.

Here’s a picture of the finish panel falling off my arch.

This image is hidden for guests.
Please log in or register to see it.




What I did first was to remove all the finish panels, the seats, seat backs and all the wiring from the arch. I labeled the wires and saved the finish panels to use as patterns later. Once the seats were removed, access to the bolts that hold the arch in place was possible.

This image is hidden for guests.
Please log in or register to see it.



This image is hidden for guests.
Please log in or register to see it.



Even though the bolts were Stainless Steel, most of the nuts would not come off. I ended up either breaking or sawing them off. Once the arch was loose, the marina picked it off the boat with their fork lift. We strapped it to the top of the Jeep and took it home to be rebuilt over the winter.

This image is hidden for guests.
Please log in or register to see it.



This image is hidden for guests.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

R&Jonthebay
Reed & Jan
1988 3218-TAHITI

3218 arch rebuild 13 Aug 2012 22:33 #2

  • R&Jonthebay
  • R&Jonthebay's Avatar Topic Author
  • Offline
  • Platinum Member
  • Platinum Member
  • Posts: 1421
  • Thank you received: 60
Here’s a picture of some of the rotten blocking at the point where the arch attaches to the fly bridge.

This image is hidden for guests.
Please log in or register to see it.



This is where I lost the pictures so you’ll have to bear with more of my descriptions.

I removed all of the rotten blocking using a Fein multi tool, a hammer and a chisel. It took about six hours….spread out over several days…and I only hit my hand a half dozen times…..coulda been worse.

When it was removed, it left a channel for the new wood to be fit into. Here’s a picture of the new blocking being ground to fit the shape of the arch so you can see where the old blocking was.

This image is hidden for guests.
Please log in or register to see it.



I decided to use 1x3 and 2x4 treated lumber as the replacement blocking. It was winter and I was able to find lumber that had been sitting long enough to dry out.
On the top section of the arch, I started at the ends and worked toward the center, cutting and fitting an 18’ piece one at a time. The shape of the arch was traced and then cut on the bottom side of each piece so that it fit into the channel and followed the curve at that point. The top part of the wood was left protruding out of the channel. The sides were done in the same manor. Once all the wood was fit, it was sealed and glued into place with epoxy.

After the epoxy had cured, a disc grinder was used to grind the excess protruding wood to follow the inside curve of the arch. Again, the raw wood was sealed with epoxy.


The vinyl trim was cleaned up and reused to save money. This time 4200 was used to glue it into place and seal the joint to prevent future water intrusion. Only a few staples were used to hold it in place before taping.

This image is hidden for guests.
Please log in or register to see it.



This image is hidden for guests.
Please log in or register to see it.





I used StarBoard for the new finish panels. The old panels were used as patterns; the new ones were cut big. It was difficult to fit the panels because the arch was not a true and even curve. It took multiple cuts with a router, jig saw and sander to get them to fit nicely. Clamping the panels to the arch helped to hold them in the position they needed to be in to get the right line. SS pan head screws were used to secure them in their final position. Plastic screw caps could be used if hiding the screws was your preference.

This image is hidden for guests.
Please log in or register to see it.



This image is hidden for guests.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

R&Jonthebay
Reed & Jan
1988 3218-TAHITI

3218 arch rebuild 13 Aug 2012 22:35 #3

  • R&Jonthebay
  • R&Jonthebay's Avatar Topic Author
  • Offline
  • Platinum Member
  • Platinum Member
  • Posts: 1421
  • Thank you received: 60
Here are a few pictures of the arch being mounted back on the boat. Once again the marina helped lift and hold it in place with the forklift while we bolted it back on.

This image is hidden for guests.
Please log in or register to see it.




This image is hidden for guests.
Please log in or register to see it.




This image is hidden for guests.
Please log in or register to see it.




This image is hidden for guests.
Please log in or register to see it.




This image is hidden for guests.
Please log in or register to see it.




I did not make the cut outs for the old lighting in the side panels. A new LED overhead light was installed in the center of the arch. It seems to be enough light for our purposes. If at any time we feel the need for more light, LED surface mount fixtures can be added to the side panels.

I personally didn’t feel that this job was overly difficult and that most people with moderate skills could easily achieve satisfactory results.
The following user(s) said Thank You: DIVErsion, Bacon

Please Log in or Create an account to join the conversation.

R&Jonthebay
Reed & Jan
1988 3218-TAHITI

3218 arch rebuild 14 Aug 2012 01:43 #4

  • nickatnite
  • nickatnite's Avatar
  • Offline
  • Elite Member
  • Elite Member
  • Posts: 658
  • Thank you received: 27
Does the wood completely fill the channel between the arch and the flybridge where it bolts in? Ours split at the bottom aft bolt and the wood pulled away from the glass.

Please Log in or Create an account to join the conversation.

Nick
1988 3218 "Selkie Song"

3218 arch rebuild 14 Aug 2012 02:15 #5

  • R&Jonthebay
  • R&Jonthebay's Avatar Topic Author
  • Offline
  • Platinum Member
  • Platinum Member
  • Posts: 1421
  • Thank you received: 60

nickatnite;711515 wrote: Does the wood completely fill the channel between the arch and the flybridge where it bolts in? Ours split at the bottom aft bolt and the wood pulled away from the glass.


Yes, as much as possible. I put some SS screws through the channel and into the wood on the inside to help hold the wood. I think that there is still a little space between the blocking and the fly bridge so I didn't over tighten the bolts.

Please Log in or Create an account to join the conversation.

R&Jonthebay
Reed & Jan
1988 3218-TAHITI

3218 arch rebuild 11 Nov 2012 17:13 #6

  • Capt. Poppie
  • Capt. Poppie's Avatar
  • Offline
  • New Member
  • New Member
  • Posts: 51
  • Thank you received: 0
Hello Reed,

Was there any noticeable expansion of the Starboard panels?

Did you bolt arch back on like the factory,(countersink bolts and put caps on the fiberglass), or did you through bolt it leaving bolt heads exposed?


This is an unexpected upgrade for me, the arch was almost torn off by the travel lift, but i then realized how rotted the wood was and now I have something to do this winter.

Thanks,

Bill

Please Log in or Create an account to join the conversation.

1988 3218MY
Twin 305's

3218 arch rebuild 11 Nov 2012 23:55 #7

  • Blues46
  • Blues46's Avatar
  • Offline
  • Senior Member
  • Senior Member
  • Posts: 247
  • Thank you received: 0
Nice job Reed!!

Please Log in or Create an account to join the conversation.

3218 arch rebuild 05 Dec 2012 13:10 #8

  • R&Jonthebay
  • R&Jonthebay's Avatar Topic Author
  • Offline
  • Platinum Member
  • Platinum Member
  • Posts: 1421
  • Thank you received: 60

Capt. Poppie;734200 wrote: Hello Reed,

Was there any noticeable expansion of the Starboard panels?

Did you bolt arch back on like the factory,(countersink bolts and put caps on the fiberglass), or did you through bolt it leaving bolt heads exposed?


This is an unexpected upgrade for me, the arch was almost torn off by the travel lift, but i then realized how rotted the wood was and now I have something to do this winter.

Thanks,

Bill


Bill, sorry for missing your question for so long.

There was no noticeable expansion of the starboard....but then, I didn't really pay that much attention to it after it was finished. Had it moved much, it would have cracked around the screw holes or buckled......I would have noticed that.

I re-installed it using the existing factory holes and found new caps at Home Depot. I didn't want to mess with trying to fill and glass the old holes.


Because of the way the arch mounts to the bridge, stopping water from getting behind it is almost impossible. Perhaps running a bead of 4200 along the top and sides (where they meet the bridge) after installing would help.

Please Log in or Create an account to join the conversation.

R&Jonthebay
Reed & Jan
1988 3218-TAHITI

3218 arch rebuild 05 Dec 2012 13:11 #9

  • R&Jonthebay
  • R&Jonthebay's Avatar Topic Author
  • Offline
  • Platinum Member
  • Platinum Member
  • Posts: 1421
  • Thank you received: 60

Blues46;734262 wrote: Nice job Reed!!


Thanks Tom.

Please Log in or Create an account to join the conversation.

R&Jonthebay
Reed & Jan
1988 3218-TAHITI

3218 arch rebuild 07 Dec 2012 23:14 #10

  • Capt. Poppie
  • Capt. Poppie's Avatar
  • Offline
  • New Member
  • New Member
  • Posts: 51
  • Thank you received: 0
Reed,

Thanks again.

Bill

Please Log in or Create an account to join the conversation.

1988 3218MY
Twin 305's
  • Page:
  • 1
Moderators: whiskywizarditsabowtime2
Time to create page: 0.106 seconds
Powered by Kunena Forum