Balsa cores

[Saltdog]

Sometime in 2001 Albin stopped using balsa and started using foam cores. While I am sure there was a reason for this, the fact is there must be 450-500 boats out there with balsa cores.

Has anyone ever heard of or had any problems with the balsa cores in an Albin 28?

[Merry Kate]

I hate to start off my 1st post with a negative, but I spent last winter digging the rotten balsa core out of all 5 cockpit hatches on my 28 TE (1996 w/ motor box deck). Had to replace a lot of the core, re-skin them with cloth/epoxy, and paint. The problem areas were around the penetrations for the lift handles and hinge screws where Albin just drilled directly through the laminate with no resin, caulk, or anything sealing the exposed core. I knew about it for awhile, but did’nt get motivated until some delamination started.

I think they did an OK job with the through-hull penetrations (replacing the balsa with plywood - not great, but better), but the deck is a different story. I have’nt had them all off, but I’m sure that every through-deck penetration is only caulked and the core has not been properly backed-out & glassed. Will last for 5-10 yrs, but the sealant eventually leaks. Not trying to scare anyone – just be aware if you have an older model. (I just recalled having to glass around the edge of the engine vent cutout a number of years ago, which had exposed core without even sealant. Had to do the same to the anchor locker covers.)

Basically, Albin builds good quality, strong boats, but the reason a ‘28 costs $100+k instead of $200+k is because of “details” like this. Known and accepted, they can be dealt with. Left uncorrected, they can (will) ruin a great boat. (BTW, it’s not good to get water in a foam core either, just not as deadly as balsa.)

I have a bunch of before/after pictures from the job, but they bring back bad memories.

I’ve been looking for an Albin message board for 10 yrs. Glad to have finally found you all! Sorry for the bummer post. Other than a few inevitable snafus like this, we've LOVED this boat.

[mhanna]

Before I bought my 2001 (just a month ago) I was looking into the balsa issues. I called Albin and they told me that they stopped using Balsa in the core starting with year 2000. I guess I will remove the engine vent and see what rough finish is there....
Just poking around over the last few weeks I also noticed that the pulls to the deck plates seemed to not be sealed... silly I thought, with water being on the deck of course they would seal them. Oh well I guess I will take them out and coat the inside with epoxy. Small things like this will prevent large work later.

See an earlier post on topic
viewtopic.php?t=394

Matt

[chiefrcd]

Yep...it's not a bad job to go in and reseal those holes, just takes some time and patience. I also removed and sealed the roof mounted hand rails, as they too had some "punky" balsa spots. I keep my boat under a boat shed so it has a chance to dry out pretty well. It really helps when trying to get ahead of the leaks.

[mhanna]

Chiefrcd, what made you rebed the handrails ? where they loose or did you see a leak ? I may have to add this to my list of things to do, but I checked and everthing 'feels' ok.
My boat also has 10 gunnel and transom mounted rods holders, 3 down each side and 4 across the back. I plan on checking them as well for proper sealing.

Thanks
Matt
[/code]

[chiefrcd]

When my boat was surveyed the starboard handrail was the only spot that tested high on the moisture content meter that the surveyor used. He told me that I needed to removed the rails and allow the moisture to dry out. I went ahead and removed both and allowed them to dry out. Only one hole had moisture in it. Then I resealed them but I did install stainless steel oversized washers on the exterior side so I would have more tightning surface when I refastened the nuts and washers on the inside. I used 3M 4200 for the resealing job.

[tomcat rio]

...balsa coring was not used below the water line on the early albin 28's (mine's a '93 hull number 11). is that correct?

[med2alfa]

Tomcat,

Below is most of a note I received from our local Albin dealer regarding questions I had about coring. Although it doesn't specifically address your question one can surmise from the comments from the dealer in the last two paragraphs that balsa coring was used pre 2000. The following was addressed to the dealer from Bob at Albin.


"We are currently using Airex C-70 foam in hull bottoms..... Topsides of hull from Chine up are solid laminates....Where Penetrations go through the hull, Foam core is removed and replaced with solid glass...Core thickness varies from model to model....



Decks are cored with End Grain Balsa core on most horizontal and vertical surfaces.... Thickness varies from model to model..."





Airex C-70 foam:


Description & Characteristics

A unique closed cell, cross-linked polymer foam that combines high stiffness and strength to weight ratios with superior toughness. It is non-friable, contains no CFCs, has negligible water absorption, and provides an excellent resistance to chemicals. A fine cell structure offers an excellent bonding surface that is compatible with most resins and manufacturing processes. It is ideally suited as a core material for a wide variety of light-weight sandwich structures subjected to both static and dynamic loads in service.

high strength and stiffness to weight ratios
good impact strength (highest elongation in class)
low resin absorption
high fatigue resistance
good fire performance (self-extinguishing)
sound and thermal insulation
non biodegradable
good styrene resistance




Hope this helps with the customer...



Thanks,

Bob



The following two paragraphs are from the dealer.


"I know from talking with them in the past that they went to Airex coring in 2000. So all boats prior to 2000 were cored with End Grain Balsa. Prior to that (such as back in the 80’s or 70’s) Albin was building their boats overseas and not here in the US. I’m not 100% positive if they were coring the hull or if it was solid glass. The current employees in Rhode Island are not sure either – so it may take me some time to get an answer on that one.



So I’m not sure if I answered your question entirely, but I will say that in the almost 10 years we’ve been a dealership we’ve haven’t really seen any issues from our customers concerning the coring material. If anything, one of our customers said his life may have been saved by the cored hull. He was traveling 18 knots and hit a rock square and the boat did not take on water, did not sink, etc. Coast Guard/Surveyors involved felt that if the hull would have been solid glass, the impact would have caused some severe fracturing and it they felt that the boat probably would have sunk."

[tomcat rio]

..i would think that a major problem with balsa water penetration would occur during winter storage below freezing, but haven't ever heard of hull damage due to ice expansion. it may be that water may just drip out while on blocks. could be its more of a problem with boats that never come out of the water.