Alberg 35 Hull/Deck Joint Anatomy

[brob76]

Hi Everyone,

I'm the proud new (~6 months) owner of a '62 Alberg 35 hull# 54. I'm just getting started on a fairly basic winter refit. The boat is in pretty good shape for the age with the exception of a rotten rudder and a couple of soft spots on the deck. I'll be starting a new thread about the rudder. Wondering if anyone knows the anatomy of the hull deck joint on these boats. I removed a small piece of the mahogany trim from the transom to try and expose a small section of the joint and it looks like the hull and deck are glassed together as an integral piece. In other words, I don't see any joint. Does this sound right? I would have thought it was some sort of inward facing flange. From inside the cabin, the liner obscures the area under the bulwark so I can't see anything from in there. I'm not sure if there is a leaking issue or not but after working on a few old boat refits, I know this is generally an area of concern.

Thanks,

Brian

[Rachel]

Hi Brian, and congrats on your new-to-you Alberg 35. Nice boats!

I would be fairly certain that your hull and deck were molded in two separate pieces.

As far as the exact set-up of the hull/deck joint, I'm not super familiar with the Alberg 35, and whether or not it has various "eras" of hull-deck joint (early and late boats, or etc.). Could you post a photo? We could probably make a pretty good guess from that, as there were only so many ways of joining them.

Rachel

[galleywench]

Congrats on the new boat, you won't be disappointed. They sail and look beautiful (IMHO). Of course I might be a bit biased since I also have a '62 A-35 (hull 16). I have not taken my rail off yet during my restoration because it keeps my sticky hands from grubbing up the hull when I am going up and down the ladder with a jug of epoxy. I had this same discussion not too long ago in another thread and I think I'll cut a piece of the toerail out this weekend to see how the joint ticks (I'll post some pix). My understanding of the A-35 joint is that the 2 flanges of the hull and deck are mated together and then glassed over. It seems like techniques varied from year to year, some with mechanical fasteners, some without. I can't be certain until I pull mine, but I suspect the earlier models ('61 and '62) may have been a glass only joint with no mechanical fasteners.

I'll get back to you later this weekend.

[galleywench]

Attached is a picture of the joint on a section up by the bow that I pulled off this morning. I can't see any evidence of mechanical fasteners (other than what is holding the mahogany toe rail in place. I don't know what is lives inside of the bulwarks but is approximately 2 inches wide and 3 inches high (from deck level). The joint appears to be solid and tight in this section and if the end grain fiberglass wasn't discolored, it would be hard to find the joint location. I am curious what I'll find when I get to some higher stress areas like around the chainplates.

Anyway, hope this helps.

[Quetzalsailor]

Perhaps you can see the inside up in the chain locker and the lazarettes.

Quetzal's is fiberglassed and tabbed, rather than sealed and bolted. The joint is bolted with the toerails and, though I haven't bothered to count, there maybe a few others in between. Pretty reasonable to assume some mechanical fastening while bonding.

[brob76]

Thanks for the pics. Mine looks exactly the same where the trim was missing from the transom. I was really hoping to avoid that project. I glassed a hull/deck joint on a Vanguard a few years back and it was a long and tedious process. Have you ever had any leaking issues from the joint?

On another note, I've been following your recore project on your blog. I just cut up the skin on the foredeck today. The balsa core was completely soaked but was amazingly still holding its bond in many places. The PO had the best of intentions but failed to seal the core when installing a chain pipe, windlass and oversize cleats. Other than the foredeck, I have a small area on the cabin-top to recore and hopefully that will be it. Was there any reason you decided to lay down new glass instead of reusing the old skin?

[galleywench]

Was there any reason you decided to lay down new glass instead of reusing the old skin?

I think the general consensus on the issue is that the work involved to get the old skins to a satisfactory state where they can be re-expoy'd to the new core may exceed that of doing a new layup. Also, if your not careful, it would be easy to get voids in your layup between the old skin and core. I think vacuum bagging will reduce the risk, but that opens up a whole new can of worms.

I believe Tim has a sidebar on his Glissando restoration site that discusses this issue.

For smaller areas I wouldn't hesitate to reuse the skin, especially if you need to match the non-skid pattern. You still need to tie that skin into the rest of the deck, not just the core, so you would end up beveling both the existing deck area as well as the skin your reusing. Of all the nasty recore jobs that are require, I personally hate grinding bevels into the surrounding deck area because it is SOOOOOO messy. I'm sure it would be much more pleasant if you had a real dustless grinder, but with my old Makita 4 inch grinder and 24 grit discs, the mess is absolutely astounding. 6 months after grinding about 50 feet of bevel for part of my recore, I can still find itchy dust lining the inside of the boat shed without difficulty (even after I shopvac'd the entire shed after I did the grinding).

[brob76]

I sort of answered my own question on this topic. Went to cut up more of the old skin yesterday and ended up ripping it to shreds in the process. I think I'm going to use the method recommended here and laminate a new skin with 1708 biax. I was really surprised to find how wet the core was and how far the saturation extended. I could wring most of it like a sponge.
I found it interesting that Magic, being the same production year as Auriga, used plank core while Auriga had end-grain blocks.

[galleywench]

I found it interesting that Magic, being the same production year as Auriga, used plank core while Auriga had end-grain blocks.

I think production changes were par for the course, but a midyear change is a bit odd. Magic is hull #16, so they probably learned a few things in the 35 or so boats they built in between (like the fact that capillary action is not something you want in your core). Or maybe it was just whatever they had in supply at the time. I believe a ran across another A-35 owner with a '64 who also had a balsa plank core.

[Hirilondë]

End grain blocks absorb more resin during lamination and produce a better bond between skins and core. As far as water getting in and traveling due to capillary action or what ever I don't really think it matters. Once water gets to the core you have a problem regardless of orientation of the grain. Like all production boats from the 60s there were evolutions in processes and materials and there was the use of what was on hand. We will probably never know why some things changed as they did.

[Quetzalsailor]

I don't think there's much advantage from the longevity standpoint between endgrain balsa or plywood core, unless the balsa is kerfed and the kerfs are full of epoxy resin. That's touted as isolating the travel of water through the core, but how would you ever know if it was done right? The endgrain is supposed to be stronger in shear.