New Member Lots of Questions

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

willyok

Member
Joined
Sep 25, 2018
Messages
12
Reaction score
0
Hey there guys, I am new to the forum and this is my first post.

Twelve years ago, my brother and I purchased a 1984 21' Westcoaster Bayrunner. We used the boat in the San Francisco Bay and off the Northern California Coast regularly for about two years. I joined the military and use of the boat became very infrequent as I was overseas and my brother just wasn't comfortable going out without me. The boat sat mostly uncovered for around 9 years with very little use other than running the engine.

Currently I am back in southern california and have towed the boat down to asses the project, now for my questions.

The Vinyl wrapped plywood floor and side panels have all but completely rotted away and need replacement. They where originally fastened to the hull/stringers with SS screws and washers that constantly vibrated loose and required me to keep a screw driver in one of the rod holders.

QUESTION #1: Is it possible to use rivets to fasten the new decking and side panels? If so, what kind/style would be appropriate and water tight?

Upon getting it home and in my yard, I removed the 90hp mercury two stroke, Kicker bracket, and four transducer mounts that had been installed along the way. After cleaning a LOT of silicone from the transom, I found about ten BB sized holes in the outer transom skin. I picked and probed the transom wood with an awl in all accessible locations and it is very solid. This part of the project leaves me with two questions.

QUESTION #2: My impression of the transom wood is that is is very solid and does not need to be replaced. As for the outer skin of the transom, I am left with a couple options that are acceptable in my opinion.

Option #1: Remove/cut the outer transom skin and replace with a new sheet of aluminum. (if I go this route, I would also end up replacing the wood or at least epoxy coating it.

Option #2: (and what I am leaning towards): Clean the exterior skin thoroughly and weld a completely new transom skin over the existing compromised one. This Idea seams far easier and I believe the repair would far outlast my ownership.

QUESTION #3: There are three stringers/supports attached to the transom. Each stringer its attached with six (approx 3/16") machine screws going through the transom. What should I use to replace these? SS machine screws with nylon washers? OR would an Aluminum rivet of some sort be more Ideal?

I appreciate any and all feedback and will take and post some pictures later today.

Will
 
I woud first determine what caused the pin holes in the transom. If a saltwater boat, most likely the wood was not treated with anything, so the salt that got left in there from waves coming over the stern started to attack the tin.

Q1 - I completely remove and replace all of the transom wood. Then see what condition the exterior skin is in. If you look at my post where I had a put in new transom skins - inside & outside - back in, you will see that once a salt chloride precipitate attack starts INSIDE the aluminum, you cannot get rid of it. It must be cut out like a cancer.

Q2 - I’d hold off on that and would see what the skin looks like after you clean it up some. But I am not a fan of welding on a new outside piece ... especially if the old one still has ‘issues’.

Q3 - Do you mean “knees” more than the stringers? Do they go from the floor (riveted in place) then up on a 45° angle to the transom? If so, those are knees, not stringers. Regardless I am a big proponent of thru-bolted stainless steel (SS) hardware, heatshrink over the bolt body & nylon washers under the nut & bolt head. You must insulate the SS from direct contact with the tin.

Pictures would help immensely! And THANK YOU for your service!
 
That's a very valuable boat. I just saw a nice similar one asking almost 20 grand. With that said I'd be tempted to replace the whole transom sheet and have a pro weld it up like new. Let's see pics. That's a cool boat!
 
Stumpalump said:
With that said I'd be tempted to replace the whole transom sheet and have a pro weld it up like new.
Be wary .... I'm guessing that hull is made of 5052 alloy and that is one tin that does not weld the best .... needs the proper filler, technique, AND welder or it is sensitive to cracking.
 
Thanks for all the quick replies and the advice!

Update:
I wire wheeled the transom with a very soft stainless brush and after removing all of the silicone I am rather disappointed. I counted a total of 96 penetrations in the transom skin with 16 of them being from corrosion/electrolysis.

Some of the 16 pinholes were formed on the inside presumably between the wood and the skin and some were formed on the outside under the kicker bracket, transducer mount, and main engine mount.

After cleaning and counting, I removed the inner splash well as conservatively as I could (everything is welded it).

I then saw the "knees" as referred to earlier for the first time. The center knee has a small crack but the others appear to be solid.

I was somewhat surprised that there is no interior skin, just the splash well. Additionally, the transom wood appears to have been treated with something at some time as it is very solid.

I still cant get the transom wood out because the knees are welded to the hull and the welded corner caps are preventing me from lifting it up.

At this point I am certain it needs a new transom skin. Knowing the difficulty of welding on 5052, I will pull it to my local fabricator after cleaning it fully to see what his thoughts are.
 

Attachments

  • Aluminum 1.jpg
    Aluminum 1.jpg
    135.1 KB · Views: 985
  • Aluminum 2.jpg
    Aluminum 2.jpg
    123.6 KB · Views: 985
  • Aluminum 3.jpg
    Aluminum 3.jpg
    47.2 KB · Views: 985
  • aluminum 4.jpg
    aluminum 4.jpg
    125.5 KB · Views: 985
  • aluminum 5.jpg
    aluminum 5.jpg
    59.8 KB · Views: 985
At some point Westcoaster merged with Valco and today it's Klamath. It would be worth calling Klamath to see if they fix boats or can tell you who they trust. I had the same flat bottom in the rear on a 16' Valco. Before you get it fixed make sure it does not have excessive hook in the rear last two feet of the bottom before it meets the transom. Not that it's a big problem but as old aluminium boats flex and get worked over by the waves they can hook in that area and now would be the time to pound it out and fix the knees. How are the ribs under the floor foward? Make sure the hull skin is still attachéd to the ribs and that the ribs are not cracked up. Tiny cracks here and there that look old or are by a rivit are normal and don't hurt anything but look for bad ones. Some of the Westcoasters were a little lighter and used more rivits. Is your hull welded or rivited? Both are great. Rivit boats are light and fast, welded are a little tuffer if you beat it. Glad to see yours still has the tall bow rail. Some people remove them or order without. I'm glad you posted the gem!
 
I had a very similar situation with my boat that you are having, I rebuilt mine and posted the details of it but, I can't figure out how to find a past thread I posted. Usually when you go to your profile it will give you the ability to see your threads, What am I missing?

Anyway, I had a '92 Sylvan 1448 and I had the corrosion in the transom too. In mine they used the CCA treated plywood, it is good stuff but does contain copper and will cause corrosion and needs to be insulated from the aluminum. I cut the end caps off and removed the wood, the wood was good so I epoxied it up to seal it and insulate it from the aluminum. I then glued it back in using G-flex epoxy so that there is no space for water to get in. I did this about 5 years ago and it is solid as a rock and still looks as good as the day I completed it. Wish I could give you the link, I will try to find it.

Found it, forgot about the advanced search feature.
https://www.tinboats.net/forum/viewtopic.php?f=3&t=23064&hilit=rebuild

One of the reasons I decided to glue the wood back in was to also fill in all the corrosion holes in the transom skin. It was the only way short of replacing the skin which I was not going to do. The added benefit is it also prevents water from getting between the wood and metal. I would only glue in wood that is going to last a lifetime like the CCA treated stuff OR some kind of composite board. Once it is glued up there is no taking it apart later on.
 
Do Not Use CCA or any other treated wood. If you think painting or epoxying it will permanently insulate the chemicals from destroying your aluminum, you may well be wrong.

Just buy the right stuff (Exterior Plywood) and use that.

You are risking the future value, and safety, of your boat.
 
I would Say 95% of the boat is welded with the few rivets being not structural. I will call klamath (I actually passed by the factory on Sunday when I towed this down south) and see what they have to say. I have heard their customer support has always been great.

I do not see any hook or bending of the bottom area or knees but i will take another look when inspecting all of the frames.

I wasnt going to use any CCA just epoxy coated exterior ply. The bigger question at this point, is what im going to do with the transom skin.


I appreciate all the insight.

Will
 
willyok said:
The bigger question at this point, is what im going to do with the transom skin.
If you look at my rebuild in my sig, I ended up replacing both skins inside and out. Your task would be much more simplified than mine, given I had a rounded hull at the garboard transition. Klamath might even be able to help!
 
If you choose to use regular untreated plywood and just epoxy coat it or something, do not glue it in like I did because eventually you or the next owner will be replacing it.
 
Don't rush to a decision. I wonder how bad the corrosion is on the inside that you cannot see. I'd also jack the boat up and inspect for corrosion under the trailer bunks. Wet salty carpet is hard on it and unfortunately some trailer wood was pressure treated. Post more pics of the corrosion and the bad spots on the rest of the hull.
 
DaleH said:
willyok said:
The bigger question at this point, is what im going to do with the transom skin.
If you look at my rebuild in my sig, I ended up replacing both skins inside and out. Your task would be much more simplified than mine, given I had a rounded hull at the garboard transition. Klamath might even be able to help!


I read your whole thread on that project, very impressive work and well beyond my level of skill. being that the boat is primarily alll welded construction, I am at the mercy of a shop to weld in a new section. I have experience with a spool gun but its less than ideal to weld on these hulls with a spool gun.
 
Stumpalump said:
Don't rush to a decision. I wonder how bad the corrosion is on the inside that you cannot see. I'd also jack the boat up and inspect for corrosion under the trailer bunks. Wet salty carpet is hard on it and unfortunately some trailer wood was pressure treated. Post more pics of the corrosion and the bad spots on the rest of the hull.


I am in no rush to get her back together. I am going to cut the corner caps and remove the wood today. Corrosion aside, I am just not comfortable with having so many holes in the skin.

The rest of the hull forward of the transom is in very good shape with the exception of the anchor/bow platform that got torn up when I left the anchor in place while trailering years ago.

I will lift the stern and take a look where the bunks ride. Its been a long time but I did install HPDE strips in an attempt to create air gaps.

Thanks again, Will
 
DaleH said:
On a GOOD note ... being an already welded boat, it may not be made of 5052 alloy, so my concerns for weldability thereof may not apply at all!!!!!

From my research and talking to other owners, the hull material is 5052.

I spoke to three different welders today and none of them expressed any real concern with welding on the 5052 with their modern welders and skill level.

One welder came to look at the boat and gave me a price of $500 to weld in a new transom and re weld the transom corners and splash well. That is with me doing all the fitting and cleaning before he gets it. I asked him about the idea of welding a sheet over the existing skin and he said he would want all the corrosion holes cut out so he can then weld the plates together in those areas.

I have not cut the transom corners yet and wont until I hear back from Klamath Boats.

While poking around the boat today, I noticed that the transom skin is actually bent in at a 90* angle like a riveted boat it is then tacked at regular intervals on the inside and welded completely around the exterior perimeter.

This weekends plan is to remove all of the poured in foam and pressure wash the inside. then inspect for any cracks on the ribs/frames. I will also get it up off the bunks and inspect under there.

Will
 
Stumpalump said:
Nice start! My 1991 18' is a little different. The flat rear skin wraps over the top and to top of the gunnel wraps down the back.

2i2bgia.jpg


Inner transom is skinned.

2mqp1td.jpg


Splash well adds strenth. And it's all welded.

epqfn.jpg

I'm not sure these pics will help but it's how the newer ones were put together.

eafkp0.jpg


2i936g0.jpg
 
Stumpalump said:
Stumpalump said:
Nice start! My 1991 18' is a little different. The flat rear skin wraps over the top and to top of the gunnel wraps down the back.

2i2bgia.jpg


Inner transom is skinned.

2mqp1td.jpg


Splash well adds strenth. And it's all welded.

epqfn.jpg

I'm not sure these pics will help but it's how the newer ones were put together.

eafkp0.jpg


2i936g0.jpg

That looks like a very nice boat. Your bilge looks deeper than mine somehow. My decking is cut back about 4'' from the transom in between the knees to allow for bilge pump and eventually a bait pump.

will
 

Latest posts

Top