many questions about repairing/replacing stringers

carboncow · #1 04-13-2014, 10:08 AM

Me and my buddy just picked up a 1988 V20 with a 225 Yamaha for close to nothing. When we drove 1000 miles to get her we were not surprised to find a soft sole around the t-top mounts. A surveyor on site gave the transom a thumbs up.

We spent this weekend stripping the center console, electronics, t-top and all hardware off...and will begin cutting the floor this week. Doing some knocking the stringers has me concerned but I"m very untrained on this topic. I know the sound of a good "ping" for testing transoms but hear quite a bit of "thud" on the stringers and a few spots seem delaminated when pressed on. I'm sure they will need repaired/replaced.

As we being to cut the sole I'll include many photos so you guys can assist but for now I'll just include a few links to galleries of the pre purchase and what we have seen to this point.

Here are my questions:

1) I did a quick drill of the stringer about 5 inches from the transom and 1-2 inches up from hull...seems to be no wood in there!!?!? Furthur up yes. Is this by design or should wood be butted to transom and floor in all areas before glassing?

2) I see on so many writeups/photos that many guys just cut the tops of the stringers and extract the wood. I've read about roto-tools and such but does this save any time/money? or just used as a guide/holder for the new stringer wood?

3) if the glass sides are left and wood extracted is it easy to lay the new wood down in there...shouldn't the wood be resined to the new glass or can there be air space...very confused by this technicque?

4) Do most of you take the whole stringer out or only the soft parts (keep cutting till you find good wood)? Do you have to "toe in" the new wood if you only take a part out?

I've done a lot of reading over the last two weeks and many many youtube videos but still have so many questions!

Here are photos of the pre purchase: http://www.carboncow.net/Other/Boats...-V20-Steplift/

Here are photos of where I'm at this weekend: http://www.carboncow.net/Other/Boats...ration-Photos/

I'll embed photos into the thread as we start cutting the sole this week. For now I have the image of the tank out. No foam. It's very strange that the tank has a hatch but cannot fit thru the hatch...we still had to cut the lip off the hatch hole. to get it out...lifted right out.

On another note I love these hulls...always wanted one but it's very interesting to see where builders cut corners and some of the questionable techniques. I can see why there are so many opinions on these boats on iboats.com and other forums! The part that really blows my mind is that 100% of everything added after the build by previous owners/dealers has no protection in cuts and screw holes...and so much bad wood because of it. Even a few of the original build cuts are questionable about sealing.

Was build quality better in the earlier boats, mid years or last years?

phatdaddy · #2 04-13-2014, 11:15 AM

welcome, nice find, looks like your getting a good start. friend just cut the tops off of the stringers, layed in new wood, poured in fresh resin &glassed the tops. working well so far.

as far as better years, i think it depends on the day it was built more that the year. the worst thing wellcraft did was not seal the drain holes where the stringeres meet the transom

good luck

carboncow · #3 04-13-2014, 11:29 AM

I don't even think I saw any drain wholes where where the stringer meets the transom...I'll have to look again. What builder doesn't seal whole!?!?! But I digress...

So are most guys having to router out the wood or does it often pull out from delimitating from the glass?

Or is it best to just cut out that which is soft only? My guess is it's most likely to be soft on the bottom so if we cut the tops and it looks hard it may still be soft at the bottom, correct?

cterrebonne · #4 04-13-2014, 04:41 PM

Quote:

Originally Posted by phatdaddy

welcome, nice find, looks like your getting a good start. friend just cut the tops off of the stringers, layed in new wood, poured in fresh resin &glassed the tops. working well so far.

as far as better years, i think it depends on the day it was built more that the year. the worst thing wellcraft did was not seal the drain holes where the stringeres meet the transom

good luck

Yep, if not for that, the stringers would last a lot longer than they do.

phatdaddy · #5 04-13-2014, 04:52 PM

cc, go to the v-20 gallery, page 3, bottom middle, vic's v20. he is the one i am talking about. he never used the seacast, went with wood.

carboncow · #6 04-16-2014, 07:39 PM

OK, we started to cut the sole out today...several photos and a few questions...

We are going about 2 inches off the entire perimeter of where the sole meets the inner gunwhale. I found a couple areas of rot that still exist in that last inch or so all the way to the where it turns into the glass of the wall. Are we OK to dry these areas, dig out anything that wants to come and fill that with a bondo type product? Again this only a 2 or 3 areas of a few inches at best.

If any areas are wet but not rotted are we OK to just get them dry and move forward? I'm talking about small areas (several inches at most) in corners or areas we'd prefer not to cut much more.

See Image A and Image B

On Image C you'll see much of the sole out showing the foam inside. This foam appears to be in good shape. It's hard, 98% dry, solid to walk on even and no smell. Can we salvage this and just cut out enough to glass in new stringers?

See Image C

OK...we drilled more holes and the stringers are shot inside....what is coming out on the bit looks like compost! Best I can tell at this point is from the transom all the way to the gas tank well is bad. Can we just take the bad area and leave any good wood ahead of gas tank area...or do most of you cut it all out and start over? Are we going to find real solid wood in the stringers or is going to be plywood...it's so think and tall...my buddy things the later!

How do any of you feel about abover putting the new floor over the old floor and having a few inches of overlap? Seal all edges of the new floor, glass the new to the old with a channel running around the permitter and then using firing strips (or similar) to place on top of the bulk heads so the floor rests on those for support?

Does anyone every screw the floor into the bulkheads to reduce noise? Seems silly that "bondo" like stuff they used to attach the floor to the bulkheads.

Liam · #7 04-17-2014, 06:05 AM

I would remove all the foam,it may seem dry but will likely be wet at the bottom against the hull. Looking at you pic i would cut the deck back a little further at the rear to eliminate more of the wet wood that is still around the edges,then fill and seal edges with thickened epoxy or vinylester.(don't use bondo in the marine enviroment).
I would not put any foam back in personally,not good with wood cored stringers.
Keep testing the stringers moving forward until you find good wood,mine were rotten all the way to the cuddy,then sister in at that point.
As far as the sole i would start fresh and not overlay the old deck,way too much uneccessary weight somewhere for moisture to get trapped.
Definitely add limber holes at the back of the stringers.
I am in process of doing the same as you on my 73,i need to update my thread but it is not easy taking pics when your hands are stuck together with resin,lol.

carboncow · #8 04-17-2014, 06:27 AM

Laim,

more questions...

1. What did you use to cut your deck? We used a circular saw that cut like butter but can only get an inch or so to the wall...the zip saw is not as fun.

2. Could you expend on the "more weight" and "trap moisture" comment, I guess I'm not seeing/understand that (but I am listening!).

3. How do you suggest the foam comes out? I think I read a guys post on using a chain saw and my buddy is a chain saw master. So do we think the foam adds to the shortness of life of stringers due holding the moisture in the area?

4. Do you suggest trying to salvage the fiberglass from the stringers as much as posible and just insert more wood?

5. What kind of wood are using for the stringers? Based on their height we are expecting to find plywood in there too!

Liam · #9 04-17-2014, 07:31 AM

Quote:

Originally Posted by carboncow

Laim,

more questions...

1. What did you use to cut your deck? We used a circular saw that cut like butter but can only get an inch or so to the wall...the zip saw is not as fun.

I used a circular saw where i could and then a sawzall in the corners

2. Could you expend on the "more weight" and "trap moisture" comment, I guess I'm not seeing/understand that (but I am listening!).

One deck on top of another is 2 times the weight( a considerable amount) and if one is sandwiched on top of the other you will likely get voids and use a ton of resin to bond them together(more weight/cost).The underside of the deck should be allowed air to reach it,allow it to breathe and extend its life,you want to put a layer of glass on the underside of the new deck core also

3. How do you suggest the foam comes out? I think I read a guys post on using a chain saw and my buddy is a chain saw master. So do we think the foam adds to the shortness of life of stringers due holding the moisture in the area?
I used a shovel,flat bar and then a scraper and finally grinding disc,most of it comes out easily,chainsaw is gonna make a lot of mess and may damge the hull if not careful
yes i believe the foam decreases the life of a wood cored stringer
4. Do you suggest trying to salvage the fiberglass from the stringers as much as posible and just insert more wood?

Cut the fibreglass about 1 inch up from where it meets the hull all the way along the stringer and then remove all the old stringer,cut new stringers to size and use the cleaned out channel you left as a guide to insert the new stringer on thickened resin,then glass the whole thing in with 1708.
A new layer of 1708 will seal you new stringers better than the fibreglass job they did at thew factory

5. What kind of wood are using for the stringers? Based on their height we are expecting to find plywood in there too!

I used 3/4 exterior grade fir doubled up,marine ply is better but cost is way higher,IMO properly sealed fir will last nearly as long. I am not sure what the original stringer material is on your year,mine was spruce but it is a 1973,others may chime in here

dan4836 · #10 04-17-2014, 05:40 PM

I am doing the same project now.

I cut out my deck, removed the fuel tank and foam. Cut the tops of the stringers and bulkheads and was planning on using Seacast or Arjay to fill the void.

What I decided to do is pick up three sheets of 3/4" A/C plywood. Cost all the wood with polyester resin. Install the 3/4" stringers back into the stringer cavity.

What I found - the stringers were made with a piece of lumber (not plywood) the bulkheads are made with plywood and are much more difficult to get the wood out.

I will be glassing over using 1708 and chop strand with at least four layers.

I was able to consult with a boat builder and he said the plywood material I am putting in is just to fill the void. The 1708 and chopped strand will be the new structural stringer.

After this is complete, I will drop my 3/4" plywood floor. I thought about using a composite but by the time I have to re-do the floor it should be many years....

My floor will be laminated with two coats of chopped strand.

I will post photos soon...