many questions about repairing/replacing stringers

[carboncow]

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/1988-Wellcraft-V20-Steplift/

Here are photos of where I'm at this weekend: http://www.carboncow.net/Other/Boats/V20-Restoration-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]

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]

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]

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]

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]

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]

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]

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]

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]

Stringers

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...

 

[carboncow]

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

Thanks and great info.

To be clear...my question about putting the sole on top of the old sole is based on my photos. As you aw I have only 2-3 inches around that permitter and we were considering putting that on top overly lapping about 1-1.5 inches. This would have a water channel all around the permitter.

Were you talking that I would pick of voids this way...or were thinking I was laying the new sole over an old/wet one?

 

[carboncow]

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.

So it was not continuous wood but smaller pieces? Are they secured (sistered) in a way to connect one another? I should comment my floor was made of chunks of plywood and not one continues piece!

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.

So you are using plywood in the stringer? Sometimes when I read this posts (no offense) it makes me question one we even pull the wood out! I'm guessing the factory glass is not amazing with a wet stringer but if you go mega-layered with glass then it really doesn't matter what is inside!?!?

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....

I've read many a post on other sites talking composites...and I think it's fine for those with $$$ and who like the wow factor, but as you stated a good wood floor should last a long time too at a lower cost.

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

What type/weave will you use? We are trying to understand all the designations people are listing.

I will post photos soon...

See my questions up in the body of the text...

 

[carboncow]

Dan,

Any to be clear...you are doing your stringers in 3/4" plywood? Marine grade or standard? We've been getting mixed info on this but we seem to believe if the plywood is heavily resin'd then it doesn't need to be marine.

Will your stringer needs be greater then the length of plywood (assuming 8ft) and if so doesn't it matter how they "butt" to the next piece?

thanks.

 

[carboncow]

Guys...I need input on "how much" 1708 to buy.

We may need todo two stringers up to 10+ feet long and the sole as you see. We can do the math I'm sure but how many yards are we talking?

Seems it's in 50" width and I'm seeing 48 yards for about $290.

Thoughts?

 

[Liam]

Hey sorry i misinterpreted what you where saying with the deck,you will be fine using the perimiter to attatch,i am doing the same.
I have saddle tanks so am raising the tanks 3/4 inch to allow for the overlap.
I am only using one layer of 1708 on the stringers,50 inch will do both my stringers,tabbed in with 6 inch 1708 tape and CSM in the tight corners.
I suspect your stringers are taller than mine though so you may need to use one length of 38 inch per stringer.
For the deck i plan to use one layer of 1.5 oz CSM on the underside then one layer of 1708 with a layer of 3/4 oz CSM on the topside.Thats with 1/2 inch ply.
My stringers are longer than 8 feet, as the stringer is made from 2 pieces of 3/4 ply i just cut one piece 12 inches shorter and do the reverse on the next section of stringer,glue with resin and stainless screws,then one sheet of 1708 over the whole stringer.

 

[carboncow]

Liam,

Glad to think average minds think alike...

comments in body of the text.

Hey sorry i misinterpreted what you where saying with the deck,you will be fine using the perimiter to attatch,i am doing the same.
I have saddle tanks so am raising the tanks 3/4 inch to allow for the overlap.
I am only using one layer of 1708 on the stringers,50 inch will do both my stringers,tabbed in with 6 inch 1708 tape and CSM in the tight corners.

How come only one layer on the stringer (I see many guys online doing multiple. Is it because you have strength in the old ones at the base and pouring in the fill will give additional stability?

I've seen the glass tape online...why are you using it? Is it easier then cutting something long and thin for tabbing needs?

I suspect your stringers are taller than mine though so you may need to use one length of 38 inch per stringer.

Yes now that I see the newer boats have only two tall stringers and from your post you have 4 shorter ones (I believe) which presents some challenge of the wood height and getting it in there. I like your idea of leaving a few inches of the stringer for a guide.

For the deck i plan to use one layer of 1.5 oz CSM on the underside then one layer of 1708 with a layer of 3/4 oz CSM on the topside.Thats with 1/2 inch ply.
My stringers are longer than 8 feet, as the stringer is made from 2 pieces of 3/4 ply i just cut one piece 12 inches shorter and do the reverse on the next section of stringer,glue with resin and stainless screws,then one sheet of 1708 over the whole stringer.


Are you stating your will glue and screw those two stringer pieces together or are you screwing your deck to your bulkhead/stringers too?

What is CSM..."chopped" or "cut" matting? Obviously you have done some glass work before with the different weight usages. If we are buying a large roll of 1708 are we fine to use that for all deck needs and just change directions? How many layers would you recommend for the decking? (I see many opinions out there!

Again, this is great stuff. Thanks for letting me parse your comments as I learn this. I got a buddy who is off the charts handy with this stuff but green with glass but I like to understand everyone process to feed him the intel so we do our boat right and safe the first time.

 

[Liam]

CSM stands for "chopped strand mat"
As far as one layer,1708 is actually 2 layers it is one layer of 45 degree woven fabric with a layer of CSM stiched to the back of it. Providing you don't use polyester resin 1708 is extremely strong and waterproof.
The deck will be screwed to the stringers and bulkheads,there will also be a layer of thickened resin on top of the stringers/bulkheads to allow for any undulations. The stringers will be screwed at the overlap permanently,when i glued the two layers of stringer together i put resin between the two and screwed and clamped them until the resin had set then removed the screws.

Glass tape saves cutting as you mentioned and is used for tabbing in.

Your stringers are taller because you have a later boat that has a self bailing deck ,the deck was raised to be above the water line and they increased the cap height to allow for the loss in freeboard.

 

[bradford]

Excellent posts!

 

[carboncow]

CSM stands for "chopped strand mat"
As far as one layer,1708 is actually 2 layers it is one layer of 45 degree woven fabric with a layer of CSM stiched to the back of it. Providing you don't use polyester resin 1708 is extremely strong and waterproof.
The deck will be screwed to the stringers and bulkheads,there will also be a layer of thickened resin on top of the stringers/bulkheads to allow for any undulations. The stringers will be screwed at the overlap permanently,when i glued the two layers of stringer together i put resin between the two and screwed and clamped them until the resin had set then removed the screws.

Glass tape saves cutting as you mentioned and is used for tabbing in.

Your stringers are taller because you have a later boat that has a self bailing deck ,the deck was raised to be above the water line and they increased the cap height to allow for the loss in freeboard.

Going to keep bugging you!

1. Why not poly...which one sticks better to the old glass too?
2. I'm trying to get a grasp on how many yards of 50" 1708. How much did you buy/use...or did I miss that somewhere?

We found one vendor selling a roll of 48" yard very reasonably but that seems like a lot if only doing one layer on the stringers and two on the deck. We'll take some measurements this weekend on the boat to come up with our theory of quantity.

3. How much resin would you also recommend based on my photo and if we had todo two tall stringers front to back. My buddy thinks 3 would due but I'm always the pessimist and think 5 is the safe thing.

 

[Liam]

Going to keep bugging you!

1. Why not poly...which one sticks better to the old glass too?
epoxy would be the best choice and will stick to old work the best,then vinylester,the fumes are pretty rough with vinylester though,then polyester which won't stick to epoxy nor is very waterproof over the long term. I am not saying it would be wrong to use poly, a lot of boat builders do,i believe the original construction on your boat is poly,but if you plan on keeping the boat for a while I would use vinylester,just get a good respirator,if money is not an issue and you are keeping the boat for ever use epoxy,lol

2. I'm trying to get a grasp on how many yards of 50" 1708. How much did you buy/use...or did I miss that somewhere?
I buy mine in smaller orders online from uscomposites,i buy enough for each part of the project,as I recall I bought 5 yards for the stringers

We found one vendor selling a roll of 48" yard very reasonably but that seems like a lot if only doing one layer on the stringers and two on the deck. We'll take some measurements this weekend on the boat to come up with our theory of quantity.

3. How much resin would you also recommend based on my photo and if we had todo two tall stringers front to back. My buddy thinks 3 would due but I'm always the pessimist and think 5 is the safe thing.

Your going to need a lot of resin,i used 3 gallons for the transom,1708 sucks up a lot of resin. You can keep the amount of resin down by building with the "wet on wet" method which makes for a stronger bond and uses less resin. I would guess 3 gallons would be about right for the stringers,make sure you order plenty of cabosil also,one quart of cabosil to one quart of vinylester will get you pretty close to a peanut butter consistency