stringer questions

[charles1961]

Re: stringer questions

Based on the pix you've posted, it's extremely hard to tell stringers (running bow to transom) from bulkheads (port to starboard).....

Try to get an area cleaned out that shows 6-8 compartments (separated by the stringers &/or bulkheads) bare down to the little bit of stringer or bulkhead (1" +/- you said you're leaving) and cleaned of foam exposing a bare hull. Similar to what WOG posted earlier:

This ^^^ looks like continuous bulkheads & possibly continuous stringers running thru notches cut out of the bottom of the bulkheads.

IMHO, you need to figure out exactly how the boat was put together originally, and try to replicate the stringer & bulkhead layout. Each boat & boat maker designs & builds boats to meet their goals, either the stringers or bulkheads can be continuous, and meet those goals.

A marine engineer designed it's structure, and as a system w/ hull, bulkheads, stringers, deck, fiberglass work & foam all working together.

sorry i did not post any newer pics yet. i was going to wait until i get some more of it cleaned out, so the pics show up better.thanks for the info of it could be either the stringers or the bulkheads being continuous.

 

[charles1961]

Re: stringer questions

is there plus and minus things to using pressure treated plywood for stringers ????

 

[jbcurt00]

Re: stringer questions

thanks for the info of it could be either the stringers or the bulkheads being continuous.

As long as you mean that it COULD be either, but that it should be put back together the way it was built, not whichever way is 'easier'

is there plus and minus things to using pressure treated plywood for stringers ????

Minus:
Often wet & heavy
More expensive, and often lesser quality wood then ACX plywood
Will often warp & twist as it dries out (you need it to be well dried before poly & bedding are applied)

Plus:
If kiln dried (even more expensive) it will last longer then non-PT plywood. But if not well sealed, and well maintained (stored bow up, drain plug out, and protected from weather) it too won't last forever.


PT in boat resto has been well covered in the resto forums. You can often find answers much faster by doing an advanced search from the resto homepage



^^^ yep, I got nothing

 

[charles1961]

Re: stringer questions

As long as you mean that it COULD be either, but that it should be put back together the way it was built, not whichever way is 'easier'



Minus:
Often wet & heavy
More expensive, and often lesser quality wood then ACX plywood
Will often warp & twist as it dries out (you need it to be well dried before poly & bedding are applied)

Plus:
If kiln dried (even more expensive) it will last longer then non-PT plywood. But if not well sealed, and well maintained (stored bow up, drain plug out, and protected from weather) it too won't last forever.


PT in boat resto has been well covered in the resto forums. You can often find answers much faster by doing an advanced search from the resto homepage



^^^ yep, I got nothing

thank you . just was curious. down here when i say ACX plywood , people keep saying BCX plywood is what i must be saying. I take it it is the same thing ???.

 

[jbcurt00]

Re: stringer questions

NOT the same, but BCX is exterior grade and could be used. I'd prefer Aurauco (sp?) MDO or ACX, if possible.

Plywood grading

That ^^ site's grading has A & B grouped together, A would be better quality on 1 face then the B , otherwise ACX & BCX are the same in all other aspects.

The X at the end stands for exterior grade plywood, and is probably much more important then the A/B/C face...

 

[charles1961]

Re: stringer questions

NOT the same, but BCX is exterior grade and could be used. I'd prefer Aurauco (sp?) MDO or ACX, if possible.

Plywood grading

That ^^ site's grading has A & B grouped together, A would be better quality on 1 face then the B , otherwise ACX & BCX are the same in all other aspects.

The X at the end stands for exterior grade plywood, and is probably much more important then the A/B/C face...

ok , thank you . that clears things up

 

[charles1961]

Re: stringer questions

here are some more recent pics. the boat is more cleaned out.

 

[charles1961]

Re: stringer questions

and some more pics

 

[charles1961]

Re: stringer questions

and 2 more pics

 

[charles1961]

Re: stringer questions

as i sand and grind the the stringers is it good to sand all the way down or do you want to leave just a little and form peanut butter in the area that is not taken all the way down. i believe you take it all the way down but i thought i would ask.just curious?

 

[Woodonglass]

Re: stringer questions

all the way to clean glass.

 

[igy]

Re: stringer questions

Hi Charles sorry I am not trying to derail your thread, and this question may help anyway. I am in the early stages of a restore myself, eg full stringer/deck/transom rebuild. I am a bit confused about something.

I have a question re PL Glue that everyone talks about. I am going to use this to bed in the stringers, laminate the ply for the transom, glue the transom to the outer fibreglass skin, fillets, etc etc. Now I know PL glue is a construction adhesive, and I have seen mentioned 3M 5200. Is this a hard drying adhesive, or is it the flexible adhesive/sealent. If its the harddrying (sandable) construction adhesive wouldnt this defeat the purpose of keeping the stringer off the fibreglass to stop 'hard spots", and wouldn't using "peanut butter" also create hard spots.

If its the flexible adhesive/sealant then can you fibreglass over this?

The reason I ask this is I am in Australia and many of the products you use are not available or repackaged/branded!

One of the products that is readily available in Oz is the Selleys range, this is what I can find thats similar:

Polyurethane Construction Adhesive at SelleysSelleys Australia

So the Selleys Pro series Adhesive/sealent retains some flexibility (although still quite firm), while the Liquid Nails Platinum is "quite a full on adhesive, sandable" quote from Selleys tech support. They also reccomended the selleys aquadhere durabond for laminating the ply for the transom.

So any advice/reccomendations would be appreciated, and hopefully Charles this may answer a question for you and some others who tune in.
cheers Ian

 

[charles1961]

Re: stringer questions

Hi Charles sorry I am not trying to derail your thread, and this question may help anyway. I am in the early stages of a restore myself, eg full stringer/deck/transom rebuild. I am a bit confused about something.

I have a question re PL Glue that everyone talks about. I am going to use this to bed in the stringers, laminate the ply for the transom, glue the transom to the outer fibreglass skin, fillets, etc etc. Now I know PL glue is a construction adhesive, and I have seen mentioned 3M 5200. Is this a hard drying adhesive, or is it the flexible adhesive/sealent. If its the harddrying (sandable) construction adhesive wouldnt this defeat the purpose of keeping the stringer off the fibreglass to stop 'hard spots", and wouldn't using "peanut butter" also create hard spots.

If its the flexible adhesive/sealant then can you fibreglass over this?

The reason I ask this is I am in Australia and many of the products you use are not available or repackaged/branded!

One of the products that is readily available in Oz is the Selleys range, this is what I can find thats similar:

Polyurethane Construction Adhesive at SelleysSelleys Australia

So the Selleys Pro series Adhesive/sealent retains some flexibility (although still quite firm), while the Liquid Nails Platinum is "quite a full on adhesive, sandable" quote from Selleys tech support. They also reccomended the selleys aquadhere durabond for laminating the ply for the transom.

So any advice/reccomendations would be appreciated, and hopefully Charles this may answer a question for you and some others who tune in.
cheers Ian

Hi there Ian and welcome to the forum. I am new here and am asking alot of questions myself and new to all of this stuff. I did use the 3m 5200 on my transom . it seems to dry flexible but by the weeks end it gets very firm but not like liquid nails. if this helps. I have not heard of this product called Selleys. i am removing all my stringers now and it is a first time. I have not done any of this before so I will be confirming these things as i get there.if you have not started a post on this yet , you might try that there are alot of people that have guided me through alot of questions i have had. sorry i could not have been more help. if i hear something i will post back.

 

[igy]

Re: stringer questions

Hi Charles and thankyou, I had started a thread and there are some answers there now which have proved very helpful. hope all goes well with the project I will be watching closely as I work through mine

 

[charles1961]

Re: stringer questions

here are some new pics, hope you can see the faint stringer lines and bulkheads. my guess is that the stringers were one solid piece with a whole bulkhead at the end and pieced bulkheads in between. What is the best way to layout your stringers and bulkheads ????

 

[charles1961]

Re: stringer questions

and some more pics

 

[charles1961]

Re: stringer questions

and more

 

[charles1961]

Re: stringer questions

and more

 

[tpenfield]

Re: stringer questions

Making the stringers a whole piece and then the bulkheads in sections should be OK. Fully fiberglass the wood structure for strength, etc.

I assume you are going to remove what looks to be that last bit of stringer in the engine compartment?

 

[Woodonglass]

Re: stringer questions

Study your previous pics, and hopefully you recorded all the measurements. You should replace the stringers, and bulkheads,motormounts, and transom in precisely the same locations as they were from the factory. the transom angle and parallelism is very critical so make sure you study up on that to ensure correct alignment of the motor with the outdrive.