rebuild radar arch in place?

[Woodsong]

So the underside trim on our 4550 is coming loose in a couple of spot. Predominately this seems to be due to loss of solid backing where the trim is screwed into the arch. I am sure that has been from water intrusion. The arch has no sag to it at all. I am toying with how I want to address this...could do a full arch replacement with aluminum piping or rebuild it. If I rebuild it- has anyone done so without removing the arch? Given the size I'd just as soon not take it down though I am sure I can get our marina forklift to lift it up for me in an idle moment and set it in the back of my truck. For those that have done this before me- what did you find that worked easiest?

[skye_peak]

remove the inner panels after marking the screw locations on the hard surface.

Using a flat blade type drill,drill out the rotted area where the screws attach inner surface to the underside of arch

epoxy pieces of large dowel into the holes you drilled

refasten the inner panels

It's not a proper repair or permanent but will buy you some time if you choose to ignore the continued rotting of the arch's interior

[ksanders]

Woodsong wrote:
So the underside trim on our 4550 is coming loose in a couple of spot. Predominately this seems to be due to loss of solid backing where the trim is screwed into the arch. I am sure that has been from water intrusion. The arch has no sag to it at all. I am toying with how I want to address this...could do a full arch replacement with aluminum piping or rebuild it. If I rebuild it- has anyone done so without removing the arch? Given the size I'd just as soon not take it down though I am sure I can get our marina forklift to lift it up for me in an idle moment and set it in the back of my truck. For those that have done this before me- what did you find that worked easiest?

There was a photo of a alumanium arch on a 45 floating around here somewhere.

I thought it look's great.

[Guest]

Kevin, we did it in place on our 89. Using a combination of tools including a dremel we cut away all the wood and then replaced it with trex. We then fiberglassed over the trex after that. It's messy and takes time but worth it in the end.

45mike

[MerlinV]

Another alternative to rebuilding the existing arch, or replacing it with a new tubular version, could be to update it to the 4788/490 style arch.

I realize that this is not a purist approach, but someone in the PNW has the molds to do this. Each year at the Roche Harbor rendezvous, a 4588 named 'Rhubarb' has the later model arch conversion (forward facing) - The fit and finish looks factory, and maintains a nice balanced look to the boat.

Looking closely at the arch, there are many differences to the 4788/490 arch to obtain the correct fit on the 4588, but the finished appearence makes it look the same. If anyone knows who has the mold, I'm sure that they will chime in here.

[smitty477]

"Another alternative to rebuilding the existing arch, or replacing it with a new tubular version, could be to update it to the 4788/490 style arch."

Not a bad idea but they are a different width.

We rebuilt ours in place aqnd it was not that bad of a job.

If it is not cracked or sagging already than reinforcing is not too hard as you have great directions above on how to get the 'skins' off and rebuilt.

Hope this helps

[kwb]

It can be done but there is no way I would do it.

First it will take a lot longer to gut, crib, glass.

Second you will have all sorts of masking required below so you don't drip on decks

Third you probably won't do as good of a job.

It only takes a couple hours to remove an arch even if fully decked out with every toy known to man. Even if you don't take it home working so gravity isn't fighting you on the upper deck would be way faster. If you know what you are doing you should be able to take down one day and gut the rot, and cut the new core pieces. next day do layups and get the glass work done, third is reassembly.

[Guest]

Hello all we just rebuilt ours and did it in place. Ours was saving and had kind of upholstered nagahide on the outside. Saying or not it was ugly as sin. We paid a guy who was not a boat guy,... But very good with fiberglass to do the repair.

He used right angle aluminum screwed to the existing wood. He then glassed it in, I think after cutting out some punky wood.

For the outside finishing he used a plastic slightly off white material that has a bumpy finish, so does not look cheap or "plasticy" he used many closely spaced ss screws to suck the plastic in place.

The result is better than I had hoped for and is very stiff. If anyone wants pictures please send me a note with an email adress and I will forward some pictures. I have never succeeded in learning how to post pictures here. I know "it is easy".........but I only this week learned how to send an attachment on an email.

[Guest]

I am in the process of rebuilding my arch. (still) What I found is that the rot was only about 1/2--3/4 inches deep and mostly at the location of the screws that hold the panels on. The wood is close to 2" deep. A very easy fix would have been to just use longer screws that could grab into the solid wood below the rot.

The other issue in my situation was that the panels were also rotten and needed to be replaced as well.

[Guest]

I am also in the process of rebuilding the arch on my 3888. I had to replace all of the wood at the base where the bolts attach. For this I used pressure treated 2x4 tabbed in with fresh fiberglass. For the small 3/4" pieces that the panels attach to I used PVC material from the local Lowes store. As with most of the other submitters on this thread only the top 3/4" of the wood was rotted so I removed it with a router and am attaching the PVC material to the remaining wood with 3M 5200 and SS screws. I am using 1/2" Celtec plastic material to replace the panels and reupholstered with fresh naugahide and welting. I still have to paint and rewire before I re-install.

Regarding removal versus fixing in place... it was a very simple process to remove. It took 4 of us about 45 minutes to disconnect and remove the arch. I will let you know how the reinstallation goes.

Island Time 3888 Gloucester Point, VA

[Woodsong]

Well all may not be so bad. I have had so many items to dig into and only so much time so radar arch has not been high on my list. Good news is that I looked at further I realized the underside trim is starboard that is relatively new. It looks like they already recored it and the starboard trim is just loose in a few spots. It was blowing 25-30 mph today and not exactly warm out so will leave it for a warmer day.

Good news is that I replaced the rusted up solenoid on the dinghy davit motor and got it working (also found out it must be hard wired b/c the davit power switch and the master 12V switch did NOT kill power to it!) and hooked up and tested the washer/dryer for the first time and it worked great too. Stripped the teak on the foredeck toerail yesterday (about 5-6 hours work) and will soon sand down the cockpit combing (no varnish there but it is greyed out) before I start putting on 8-10 coats of epiphanes. Even began scrubbing out under the engines today and new oil mats so I can see if we have any active leaks but after 45 hours of run time on them on the delivery trip home and no oil burn I think we are good to go on that front!

[capnken]

I rebuilt my arch on my 4588, and can offer some info for you.

First, when you remove the interior it appears you are looking at the inside of the arch... you are not...the way they built them, there is a balsa core under that spray in mat you see inside. Most of the arches people rebuild do not address this real issue... if your arch 'sags', you likely have water intrusion into this core.

I made a jig for the arch to maintain it's port-stbd dimensions and support it, and lifted it off the boat with a travellift. when I got it home, I ground out the inner mat and literally scooped out the dead balsa core. I was left with a gelcoat outer shell about 4mm thick. I put it on the jig I made, and fiberglassed in 3/4" pressure treated plywood all around the edges, and created a nice rigid 'U' shaped shell. Next, I used a 7/16" marine grade plywood on the inside where the padded panels were and glassed that in, leaving a hollow arch completely enclosed. I then gelcoated and sanded, and shot the whole thing with a poly-urethane paint to match the boat, and cut 'pie' hole access on the inside at the base to allow thru-bolts access for re-attachment of the arch, and one access under the radar unit in the center. The entire arch was now a sealed unit keeping out any moisture. I have enclosed a picture of the arch on the boat... sorry I don't have any close-ups. Hope that helps. Good Luck!

Attached files [img]/media/kunena/attachments/vb/659792=25061-SYS Projects 018.jpg[/img]

[Guest]

Before you continue rebuilding & repairing your Bayliner Factory arches; consider a new aluminum arch from Atlantic Towers. They can be a great solution and you can get hinged versions. Advantages of Atlantic Towers Anodized aluminum aches over

the OEM fiberglass arches:

1. They will NEVER rot or crack
2. They are lighter
3. You can see through them so you have better visibility in your stern quarters
4. They can be hinged to provide a MUCH lower air draft (14.5' on our 3818)
5. They weigh much less than the OEM arches (less than 100 lbs)
6. You can EASILY climb up on them to fix your radar & other antennaes
7. They look better & give our boats an updated look without taking away from their classic lines

I will post a few photos of our new arch tomorrow AM if I have time. In the meantime we are very happy with the Atlantic Towers solution which liberated us from the older arch & it's weaknesses

Ken

[Guest]

Can someone post pictures of what the arch is supposed to look like on the inside? I purchased mine dissasemble with the wood removed, I think. Is the whole channel supposed to be filled with wood. Mine appears to be only fiberglass.

Thanks,

Greg

[capnken]

Greg-

read my post above.... the matt you see on the inside is covering the balsa core. The wood in the inside Bayliner used is a cheap plywood that was just glued in around the edges to screw into to attach the padded panels. You screwed into the end grain of the plywood. The matt was porous, so water usually intruded into this core.

Ken