Typhoon Aft Deck recoring

[Migs]

Old core removed and cleaned up.

IMG_4026.jpg (3.03 MiB) Viewed 1470 times

Howdy All,

I've gotten motivated to start the re-coring of the Typhoon after deck. I have attached some pics. One note, if someone else attempts this and you are wanting to remove the deck skin- cut 4-1/4 inches forward from the stern. I ended up making more work for myself but cutting through the under side.

I will share more pics when able.

Looking forward to a stiff after deck. On the horizon is an outboard stiffener. The one I removed was 12" x 12" x 3/4". I am thinking of going a little bigger. In the meantime, I placed some stiffeners on the underside of the bottom skin by cramming myself up the port side bunk.

Also, am wondering if I should re-use the original deck skin or lay new glass down on top of the new core. Any suggestions? Thanks.

[Migs]

Repairs done to the cut through with CSM.

[jbenagh]

I would use new glass. When I did my cockpit sole, I tried to save the old glass but after removal it was too uneven. I didn't see how I could ensure a good attachment to the new core. It would have taken a lot of sandbags and a two step approach of gluing the old skin then grinding and patching. If I were trying to save money, it would have been about $100-120 less in glass and epoxy to reuse the old skin but a lot more labor. Then I'd worry about the joint. On a smaller area like the Typhoon, I don't expect there would be much savings at all.
It looks like you ended up going with balsa instead of plywood. I think that's a wise move.
Jeff

[Migs]

Thanks Jeff.

Yes, I'm opting for the balsa wood as it is what was used and I plan to seal all deck hardware properly- oversized hole, fill w/ epoxy, chamfer then butyl tape. I have some bits of G10 that I plan to use as backing plates for hardware. I was thinking the same about new fiberglass deck....and as you said, reuse the old skin but wonder if it adhered properly and then deal with the joint.

I'll post pics after it stops raining here and long enough to get the balsa down and epoxied over.

Miguel

[Migs]

I think I'm on the slippery slope here. I wanted a place where I could stop the after deck re-core and not have the epoxy flow down into the rotten port/starboard decks so I cut about a foot forward of the deck to make a "clean break". And of course.....found more rot. The rabbit hole of deck rot.

Forecast says it should be nice out this weekend so will get the aft deck balsa ready for placement, the biaxial cloth sized up and keep the epoxy in the cool basement until I have to make the mix.

I'll post photos as I go along.

Migs

[Migs]

Port and Starboard sides cleaned up, beveled- have to move the cover post out of the way, but have a way of knowing where to end the after deck job. Yaahooo!

[ghockaday]

Boy, that's a lot of work, but will look good when you're done.

[jbenagh]

Looking good. It's a lot of work but you're doing it right!
Jeff

[John Stone]

You are doing some good work there. Giving new life to a great old boat. I agree it's best to go with new glass. 17.08 biaxial is 1/16" thick. Simple to figure out how many layers you need to replicate the original thickness. Put the widest piece down first then the smaller ones on top. You'll even it out with fairing compound. It will all work out in the end. If it doesn't, it's not the end.

[Dick Villamil]

I have been doing the same thing to my Ty - not quite as extensive but still a lot of work. After removing the wet soggy rotten core I decided not to wait to get balsa so I built up the thickness with woven roving, thickened epoxy and several layers of fiberglass cloth but I did encase the old deck that was removed (and full of holes from a previous attempt). Did the job in between rain storms while in the water. Am at the final stage prior to using fairing compound. Has been a much more extensive job than I imagined but not have another section elsewhere to deal with. Thankfully my Toyota Tacoma has an AC outlet making it easy to use power tools away from other sources. I used a diamond blade on the dreml to cut the skin went like butter and made a nice thin cut.
Cape Dory builders didn't use much caulking for hardware on the deck that created the problem in the first place. Wish I had seen your posting 3 weeks ago!

[Migs]

Howdy,

Thanks for the comments. Finally got some weather in the 50-60% humidity range to lay out the balsa core. So I did just that and then laid up two layers of biaxial 1708. I will need to sand and fair and add another layer of 1708 and build up the starboard side forward section as there's bit of a dip despite my best efforts to brace it from underneath....oh well....that section may have 4-5 smaller layers....hahaha... I have to say, the aft deck is supper stiff.....no longer thet springy feel under foot. Can't wait to tackle the cabin top. We'll see what kind of can of worms I get into there.

[Migs]

Hi, Been slowly picking away at the deck and have made a big push. I cut out a lot of the port and starboard side deck core. Will leave fore deck for the future as it has some punky spots. One thing I did noticed on the starboard side forward deck, the core seems wet but still in good shape....just soaked. I don't think it will dry out so will remove it. I have a feeling I will find similar on the fore deck. My thought is it has become de-laminated.

I also took off the cabin top and found some interesting things. One is the small orange epoxy, perhaps?, that is amidships aft. I call it a fabrication marker. I'll have to glue it back on.

More to come....

[Migs]

Here are some photos of the cabin top with rotten core and with core removed.

I am curious to know what the material is on the cabin top mast step beam support. I drilled a hole and the same colored plastic type material came out on the bit. I am hoping it is sound enough to plug the original mast step holes and redrill with perhaps longer SS screws.

[Migs]

Cabin top core.jpg (430.7 KiB) Viewed 1168 times

I reached the download limit. Here's the cabin top with rotted core and the top cleared of balsa and mast step.

Anyone know what the materials the mast step support beam on the 1973 Typhoons were made from?

[Migs]

Sharing the rotted deck core photos. No wonder it was so mushy under foot and hollow sounding.