What type of wood is used for stringers?..Pictures of damage....

[Manipulator]

Have some problems with my motor mounts. It seems that years of leaking rams have caused oil to leak into my motor mount stringer. Take a look at the pictures. That oil in there! The things popped right off on both sides! Anyway the little piece of wood there is completely saturated with oil. Any ideas on the type of wood I should use and also ideas on this repair? The piece of wood there rests on the recess next to the stringer. The stringer itself seems ok, no oil penetrated it. Any thoughts on rebuilding/repairing?

 

[strizzy]

Re: What type of wood is used for stringers?..Pictures of damage....

Douglas fir would be your best bet. Coat it with some resin/epoxy and install. Hard to see where all the wood goes, but you really want to make sure you tie it in real nice with glass. I would recommend once getting everything back together, put the lags in, take them out, fill with resin, and reinstall.

 

[Manipulator]

Re: What type of wood is used for stringers?..Pictures of damage....

Put the lags in with the resin wet? Or pour in lag holes, let cure, drill new and reinstall?

The piece of wood there rests in a recess next to the stringer. I plan on coating it with resin and then drilling it into the stringer to hold it in good and tight. Then I will plaster the glass in.

 

[Bondo]

Re: What type of wood is used for stringers?..Pictures of damage....

That Looks to be about the size of a piece of 2X4,..........

I'd glue in a piece of P/T Yellow Pine..............

The Hard Part is going to get the Hull Cleaned Up for the Epoxy to bond well........
Gonna take some Grinding.......

And,......... Fix the Oil Leak..........................d

 

[andy6374]

Re: What type of wood is used for stringers?..Pictures of damage....

I'm not a fan of p/t pine...but that's just me.

I would either glue two strips of 3/4 marine grade plywood together or use some fir 2x4's. Either way coat them with resin and let it cure or gel before glassing over them (and of course if you are gluing the strips of ply together wet them out with resin first). Stringers are structural so you will want a good heavy glass. I'd recommend using either 1708 or 1808 DB.

Lay the stringer in a bed of thickened resin as you don't want the wood to be lying directly atop the hull bottom, which would create a hard spot. Make sure to run some fillets at the hull/stringer angle so that that glass can easily conform over the corner. THe fillets will also help ease any hard spot.

Make sure to round the egdes of the wood with your router prior to glassing to help the glass conform.

 

[Chris1956]

Re: What type of wood is used for stringers?..Pictures of damage....

I agree with Bond-o, I would use the pressure treated solid lumber. I have seen a lot of plywood in boats go bad (delaminate and rot). An alternative to the Pressure treated stuff might be some hard wood that will resin up well. Maybe some poplar or oak.

 

[Bondo]

Re: What type of wood is used for stringers?..Pictures of damage....

An Old Boat Builder once told me that Boiled White Oak is the Only Oak he would use,.....

Something about the Wood being Boiled made it about Rot Proof,..............

Donno,......... Maybe he was pulling my leg.................

I use P/T,....... Either Solid or Plywood.......

 

[andy6374]

Re: What type of wood is used for stringers?..Pictures of damage....

Pressure treated wood (the wet kind) has a tendency to inhibit the bond. Has it been done? You betcha. Has it stayed in place and not delaminted? Yes, sometimes No. It's really a matter of how wet it is.

That being said I not really trying to push one agenda or another. But with the work involved and the money spent on material's I wouldn't risk it (personally).

Marine Grade AB fir is what's used in most boat construction for areas that are to be in contact with moisture ALOT. Like stringers and a transom.

You could go with a composite and forget rot alltogether.

 

[strizzy]

Re: What type of wood is used for stringers?..Pictures of damage....

I wouldnt use p/t myself, and I would also not use plywood for where my lags are going into. Much for the same reason as I put solid stock at the tops of my stringers to attach my floor. Putting in screws or lags just tends to "split" the plywood.

I thinned the resin and put the lags back in wet.

 

[Manipulator]

Re: What type of wood is used for stringers?..Pictures of damage....

I only need maybe 1 foot of wood. What about using pressure treated lumbar and heating it in the oven to make sure it is dry?

 

[tashasdaddy]

Re: What type of wood is used for stringers?..Pictures of damage....

the new chemicals in pressure treated is not compatable with metal fasteners. the break down much faster than in non treated wood. in building construction we are having to use barriers to isolate the pressure treated, from lag bolts, and mounting brackets.

 

[Bondo]

Re: What type of wood is used for stringers?..Pictures of damage....

I've heard these Rumors Before,............
But,.....
I Haven't Seen Anything resembling these Issues,......
And,.......
I've been using Dry P/T for All of My Rebuilds.............
Epoxy Sticks Just Fine,...... No Rotten Screws,.....
None of that........
And,......
When I say Dry,........ I mean Not Wet to the Hand...........