Buying a OA 50 Mk1. Looking for Lessons Learned

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AdamWalsh

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Joined
Dec 5, 2020
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3
Good Afternoon from the woods of Vermont.

My wife and I are in contract and awaiting a positive survey on a 1979 OA 50 Mk 1.

We are excited but also know older boats have quirks and issues, as do all boats. So if there are fellow owners or captains out there that have any advice on major (or minor issues that turn into major) issues we should be on the lookout for, please advise soonest.

Also if anyone has any schematics or drawings on where systems were placed (tanks etc) that would be great. I contacted OA but they said the drawings were destroyed in a typhoon in the 1990's before things were scanned.

We are sponges. Take all information one cares to share, the good, the bad and the ugly.

Hopeful we can get to close and sea trials in the spring. Boat will live at the Naval War College in Newport RI in the summers and depending on Covid, she may be the full time home for us (2 young boys) as we work remotely and home school in the Caribbean!

Regards,

Adam
 
Welcome aboard. Congrats on your new boat (maybe). When you get it we will need photos.
 
I'm not sure about O.A.s but almost all other trawlers of that era have fuel tank issues. Hopefully the survey will catch any problems which you can then use to negotiate the price. New tanks are very pricey.. Prob over $20,000 on a boat that size

pete
 
Steel fuel tanks, aging electrical (non tinned) wiring. If there are teak decks.....LEAKS. A good surveyor should be no stranger to these issues.

Locating systems may seem daunting but it's not as hard as you think. Do them one at a time and follow the wires/hoses.
 
I have some large schematics (A0 size) but they are not particularly helpful. For boats this age a lot has usually changed!

For the sedan models fuel tanks are 4 total 1000 gallons if original. Two outboard of the engines, and two transverse at the aft bulkhead in the ER. The ones outboard of the engines are likely rusting or will have already been replaced. They were steel (5/32") and the issue was the ER vents with vertical louvres allowed rain to enter. Rust developed on the lower edges of the tanks near the hull. It typically took about 30 years for them to rust enough to leak. Replacement involves removing engines etc, and that is the ideal time to do other stuff as there is great access.

Water tanks are typically two, one about 200 gallons in the lazarette abutting the ER bulkhead, and one below the master stateroom sole on centreline of around 80 gallons. The latter will sit in bilge water (if present) and develop leaks at welded seams that are prone to being submerged. This tank is best removed by cutting away a part of the forward ER bulkhead. Just the part between the stringers. The tank can then slide aft, into the ER. When installing a new tank it can be made a little larger (longer).

Here is an old thread that you might find interesting. https://www.trawlerforum.com/forums/s43/oa-50-mk-1-a-25948.html

If you have any specific questions, just ask away!
 
Welcome to the forum! Congratulations on the new to you boat!

Can't help you so far, but maybe in the future.

Ted
 
Good Afternoon from the woods of Vermont.

My wife and I are in contract and awaiting a positive survey on a 1979 OA 50 Mk 1.

We are excited but also know older boats have quirks and issues, as do all boats. So if there are fellow owners or captains out there that have any advice on major (or minor issues that turn into major) issues we should be on the lookout for, please advise soonest.

Also if anyone has any schematics or drawings on where systems were placed (tanks etc) that would be great. I contacted OA but they said the drawings were destroyed in a typhoon in the 1990's before things were scanned.

We are sponges. Take all information one cares to share, the good, the bad and the ugly.

Hopeful we can get to close and sea trials in the spring. Boat will live at the Naval War College in Newport RI in the summers and depending on Covid, she may be the full time home for us (2 young boys) as we work remotely and home school in the Caribbean!

Regards,

Adam


Welcome. There are a couple of Facebook groups for OA owners. Including one called “Ocean Alexander Mark I Family”. They may be able to help you!

-tozz
 
Adam. Competent close inspection structural and decking important. Next close inspection all tankage. Lube test reports all engines and trans. Electrical inspec by abyc cert tech important. Goodluck.
 

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