Bottom flexing?

pblackb592 · Posted: Sun Jul 23, 2017 2:32 am Post subject: Bottom flexing?

Hi,
I am new here. I have been looking for c-dory boats for quite a long time. I have been interested in a 22 foot. I live in Seward Alaska. I have a friend who has an old boat. I think it is a 1983 22 c-dory, but it is powered by a brand new 90 horse yamaha with only 20 hours. Everything is astronomically expensive here in Alaska and boats are no exception. He wants 18k for the boat. It seems like a good deal. It has a nice galvanized trailer and the motor was almost 12k installed. So the price seems right.
I have the money and today I took it on a sea trial. During the test I noticed some things about it that will need attention. The only thing that concerned me was that the bottom in the rear of the boat flexes upward when going over chop. Is this normal. It doesn't seem like it should be normal, but if you look at the construction there isn't anything there for real structure. I don't know how much different the old boats are compared to new ones, but you literally stand on the bottom of the boat. No v for ribbing and extra stiffening. Is this not right? Is there a problem with this boat? Is the hull garbage. Does anyone here have an old hull boat or have experience with the old ones? How are they constructed. What is between the fiberglass on the bottom and the floor of the boat?

Thank you for the time. It is really appreciated, I dont want to spend a good chunk of change and have a garbage hull and be left with a motor and a trailer after a season.

thataway · Posted: Sun Jul 23, 2017 10:04 am Post subject:

The pre 1987 boats had flatter bottoms--but none of the C Dory 22's have any ribs, or strakes--(although there is a reverse chine on the 1987 on boats), Most likely the 1983 boat has a plywood core, vs balsa core--but I am not positive on when that changed.

The hull should not flex. The glass inside and outside of the core, makes it rigid like an "I" Beam. This does not mean that the hull is "Garbage" however. It is not that big a job (relatively speaking) to sample the core to determine its state. Then remove the inner layer of glass, re-core, and re-glass. It does take some time, and materials.

By sounding out the core (use the plastic handle of a screw driver or a small plastic mallet to tap), and look for dull sound areas. you can determine the approximate amount of damage. Although I have seen a few "floppy hulls", I have never seen a C Dory in that category. Even a "floppy hull" (where some of the uncorked laminate has broken down due to water intrusion into the glass structure, repeated flex cycles and the glass/resin laminate has become flexible) can be repaired, by putting in "stiffeners and additional inner glass.

Owners in AK have done core replacement. Boats which are subject to freeze thaw cycles and have any holes in the core (even screw holes) can have delimitation due to water intrusion, accelerated by the freeze thaw cycles. Being out in the weather accelerates the process.

Hare you discussed the problem with the seller? Do you feel capable of removing the inner glass, and putting in the new core? It is work--but technically not difficult.

SEA3PO · Posted: Sun Jul 23, 2017 12:08 pm Post subject:

I rode in a boat that had a hull delaminating.... their was a "Wosh" of air that came from the cabin every time we hit a large wave....yet the hull looked good when on the trailer....it was only when they cut thru the gel coat that you could see the delamination.... totaled the hull. it was the later style boat ...like most of us have.

Joel
SEA3PO

oldguy83 · Joined: 22 Mar 2013 Posts: 44 City/Region: minnesota

I owned an 1985 for a number of years,the bottom is 1" or 1.25 inches of non-marine plywood. Most of the older classics have had trasom problems with leaking at the two cockpit drains filling the lower trasom with water which then wicks overtime into the unsealed end of the non marine plywood, soaking it to the point of losing strength. The best thing to do is pull the two drains (very easy) and see how much water and wet balsa core comes out.
Don't ask me how i know. Clock

South of Heaven · Posted: Sun Jul 23, 2017 3:10 pm Post subject:

oldguy83 · Joined: 22 Mar 2013 Posts: 44 City/Region: minnesota

One in each corner of cockpit and also one in the motorwell (3).

SEA3PO · Posted: Sun Jul 23, 2017 3:39 pm Post subject:

Run,... likety split away from that deal....I sure don't want to go out in any flexible boat......it might be worth your while to have one shipped to you...not a new one...but a good late model used one...well worth the extra money....

Joel
EA3PO

SEA3PO · Posted: Sun Jul 23, 2017 3:58 pm Post subject:

The money you save in that boat....you should invest in Life Insurance and safety gear.... You might be offshore when part A leaves part B

Joel
SEA3PO

westward · Posted: Sun Jul 23, 2017 3:59 pm Post subject:

If the boat is really flexing as you say it isn't currently safe to use. You could get a hard bid to re-core the hull bottom and transom then deduct that amount from your offer. It would still leave you with the hassle of managing the re-core but would cover you from the economic catastrophe you allude to. With plywood trapped between layers of fiberglass in a boat that old it is very likely you have rot.
Given your observation I would proceed on the assumption the floor and transom are rotten and in need of repair. Try searching the archives of this site for "re-core", or "repairing core" type threads; there are several with photos showing the scope of the work involved. Good luck!

thataway · Posted: Sun Jul 23, 2017 7:25 pm Post subject:

Ball park figures for materials for proper repair without barge shipping to AK:
3 sheets 3/4" 4 x 8 Marine ply: $200
7 gallons epoxy resin with harder: $550
50 years of 1708 cloth/mat: $500
Filler, gloves, mask, suit sand paper, paint, etc: $250
Shipping by barge???

Total about $1500 in supplies to redo the transom and aft bottom--with some assumptions--and possibly could max be twice this if you have to replace the bottom all of the way up to the seats...

Working full time, you should be able to crank out the repair in 2 weeks.

Marie and I both came up with the same max we would pay for the boat--assuming that the trailer is in very good shape: $14,000.

If wanting to go forward, when the boat is out of the water, put motor in trailering positing, and put all of your weight on the lower unit. If the transom flexes, it is shot and has to be replaced. I agree that there is a very good chance it is gone.

tsturm · Posted: Sun Jul 23, 2017 10:19 pm Post subject:

pblackb592 · Posted: Mon Jul 24, 2017 10:29 am Post subject:

So it's the cockpit deck is flexing upwards. The whole boat isn't twisting or anything I agree it is not safe to use as is. It makes sense that the core is delaminated and probably rotted. I'm pretty handy and I think I can do the work myself. The seller has agreed to reduce price based on repair cost. There is a business in town that does fiberglass and I'm going to get a quote from them. The seller has agreed essentially to sell the boat for cost of the motor and the trailer which I think is very reasonable. Thank you all for the responses. I'm assuming the transom is also rotted also so that will need to be addressed also

thataway · Posted: Mon Jul 24, 2017 11:10 am Post subject:

Keep in mind the cockpit floor is the top of the bottom of the hull...There is no "deck" above the hull, and no "Bilge" between where you are standing and the hull.

You will star by sounding out with plastic or other method. Drill some expiatory holes (just thru the inner glass--not all of the way thru. A Fein saw (Multimaster) may be a good tool to invest in. I have been using a Dremel imitation, which is fine for the few projects I do these days. Several tool companies make a battery operated version. This allows cutting up to a "Zero" line to the sides of the hull. A good grinder/sander is also going to be your best friend. You will probably use a "Slick"--wide chisel. (Mine is all metal) to remove the core and upper layer of glass, after you have cut around the area you think you want to remove. (It will turn out more than the first amount.

The reason to use epoxy is that secondary bonding is better than polyester or vinyl ester resin. Also the epoxy seals the wooden core--to prevent future issues. After you have done the repair, the boat should be good for another 40 years or more...

PM sent. Be sure and document with photos as you go. Ask the moderators for a photo album.

breausaw · Posted: Mon Jul 24, 2017 7:30 pm Post subject:

I would get this boat out of your mind, put the thought in a box and lock the lid. There are tons of better newer boats out there for sale, just keep looking.
Anchorage is probably your best place to look for a good used boat, and this time of year there are often bargains to be had by owners who are ready to step up and willing to unload their boats at a significant discount before winter.
BTW, I grew up in Seward; class of 75.
Live in the big city now, don't go out of Seward much.
Good luck on your boat searching.

SEA3PO · Posted: Tue Jul 25, 2017 12:32 pm Post subject:

I am really with Jay on this.... YOu could spend a ton of money making the boat safe...but you better never try to sell it...cause no one will want a patched boat... it's just not something I would trust my wife and kids on...even after it is fixed.... Save you money and buy a better boat...much less headaches..

I wonder about the insurance liability on the boat...even after it is fixed ...I would think a good lawyer could make the point that once unsafe always unsafe... The fact that the guy is willing to give you the boat for the price of the motor and trailer speaks volumes...

Joel
SEA3PO