77 Hydra Sport Restoration

[HSXV6307]

Re: 77 Hydra Sport Restoration

No chemical engineer here, just a thought. Seacast I think it is resin, FG with maybe something to give it more flexibility or to make it not so brittle. I could be wrong, actually most likely am wrong. I was thinking cement by itself is brittle and cracks easily, the reason why re-bars and/or fiberglass are used, so why not use FG rods for the same purpose.

 

[Yacht Dr.]

Re: 77 Hydra Sport Restoration

I think there are a few things potentially wrong with this idea.

Fiberglass rods while strong themselves are not going to add anything to the slurry mix. It will still be brittle. Same thing with rebar and concrete .. the cinder blocks themselves are still brittle in its own makup.

Secondly .. I would think pouring in a slurry mix of resin,cabosil and glass will get hotter then hell and probably crack on its own while going through its curing cycle.

I have seen a few cases where the installer cleaned out the stringer shells then slipped in his wood with a slurry mix. Of course you still have to glass wrap.

So to answer your question about inserting your wood into the stringer shell..yes you can if done correctly. Make sure the wood is fully prepped before your install. ( resin coated multiple times and then sanded with 36-40 grit.

YD.

 

[HSXV6307]

Re: 77 Hydra Sport Restoration

Like I said just an idea. I don't know much about resin properties, you guys are the expert. I cut the top of the remaining stringers. They original wood was not plywood it was 3/4" solid wood, yellow in color. I would think it will be difficult to sand the inside of the stringer. By the time I sand the inside then the outside of the existing FG there will be nothing left, it is thin. I think that what I am going to do is buy wood and use the existing channels as a guide to make the new stringers. Then, cut them down and lay new glass.

 

[Yacht Dr.]

Re: 77 Hydra Sport Restoration

I would think it will be difficult to sand the inside of the stringer. By the time I sand the inside then the outside of the existing FG there will be nothing left, it is thin.

Your not really removing layers of glass per say ..you are prepping.. you just need to get the dirt and crud to exposed FG .. not sand/grind a layer of glass off . The form is still there.

I think that what I am going to do is buy wood and use the existing channels as a guide to make the new stringers. Then, cut them down and lay new glass.

Kinda sorta what im talking about ..

YD.

 

[HSXV6307]

Re: 77 Hydra Sport Restoration

okay, so the purpose if "grinding" is not really to grind it down is just to expose a clean base, got it. I have been reading all different post and what I read is grind, grind, grind...when the grinding is going to end. I always wonder how many layer do we have to remove.

 

[Yacht Dr.]

Re: 77 Hydra Sport Restoration

I always wonder how many layer do we have to remove.

As few as possible .. depending on the repair of course.

Sometimes its grind grind grind .. sometimes its grinding to clean just enough to reach bare raw glass.

The latter is more up your situation.

YD.

 

[HSXV6307]

Re: 77 Hydra Sport Restoration

Well, have not been able to work on the boat, lots of rain this past weekend. I still researching choice of wood for stringer. My stringers were not plywood but solid wood. I have read that if plywood is used then more FG need to be use to stiffen the stringers due to its grain pattern, no all layers run longitudinal, therefore not as strong as solid wood. This probably explained why the stringer's FG in this boat is so thin, only two layers on the sides. I would like to use the same material as manufactured if possible except don't know the type of wood used. I have read to use Douglas Fir, not necessarily what was used but just a recommendation.

Juan

 

[Yacht Dr.]

Re: 77 Hydra Sport Restoration

You better know how to pick out timber then .

Personally I would use Ply .. strong stuff that ply is .

YD.

 

[Woodonglass]

Re: 77 Hydra Sport Restoration

Not sure who you been talking to but plywood is longitudinally much stronger and load bearing than timber due to the fact that the wood DOES go in bilateral directions due to the various plys. The added waterproof resin gives it an added benefit to the boat restoration business. Plywood is much better for stringers and transoms.

 

[HSXV6307]

Re: 77 Hydra Sport Restoration

Most likely I end up with ply because I am not hunting for some special-only-can-find if the planets align solid wood and most likely more expensive. If the rain stop by the weekend I will go and get a 4x8 3/4 ply.

 

[Yacht Dr.]

Re: 77 Hydra Sport Restoration

IMO the quality of lumber has been going down while the quality of ply has been going up.

I have seen solid wood split right down a grain line in a stringer before..ply would not do that.

YD.

 

[HSXV6307]

Re: 77 Hydra Sport Restoration

you have a point there, I have seen wood split along the grain also. Good quality ply does not do that due to the 90 deg. out of phase layers. This tropical storm has dump and continue to dump water here, the good thing now I can sell my property as "water front", but they better buy quick or they miss it.