new member with a 78 viper

[aaron78viper]

so the boat is sitting right now. i have a million thoughts of things i wanna do with the boat. but i was wondering if there is any advantage to adding one new layer of glass before i start laying in the core. like a little insurance for strength on the old boat. does glass weaken over time with abuse? or am i being a worry wart?

[aaron78viper]

bump for previous question?

[alaskastreamin]

I added a mat and woven roving to my hull before the core. Piece of mind going 90+ with my wife. HydroStream laid up their hulls pretty dry.
If you hit a stick or debris while at speed and put a gouge in the hull, I guess it could be "plausable" the skin might delaminate from it's layers.

If your core is properly bonded to a properly prepared surface, you should be alright.

Remember your core (balsa I'm assuming) is in little squares that are flat. After grinding, I'd be suprised if you ended up with a perfectly FLAT surface.

If you do what most do and put down a wet layer of mat and weigh the balsa on top,......the low divits will be resin rich and the high spots will be "lean".
This is why I was told by our boat builder to use core-bond putty. It's as strong as properly wet out fiberglass but doesn't care about the highs and lows.

This is probably "overkill thinking" as the other re-core projects aren't failing. Just interesting facts that we tend to overlook when rebuilding.

My build is documented on the IHR under feature topics. I spent alot of time to get good clear pictures and explain. Take a look.

[aaron78viper]

so ive began to work on the viper again when the sun is out. the transom is out, i have a sheet of 1/2 inch marine plywood ready for that. and im about 95 percent done with removing the core.. i tend to jump around from one part of the project to the other but im doing my best to keep moving on it. now that its getting closer to rebuild time, im wondering where i can find a vacuum pump that is appropriate for the project. any ideas? i will upload pics as soon as everything is ground down to the shell. not quite there yet

[aaron78viper]

did more digging now that the weather is starting to turn here.. got the splashwell out, transom 99 percent out (some wood is still planted on the outer skin). I still need to either build a jig or modify the trailer to a bunk.. so I havent cut that center stringer/airbox out yet.. it seems like it would be okay, but im nervous.

[Hippie459MN]

Your stringers there, there is core under them so your gonna want to take em out and take that core out. When your done and have everything out and cleaned up it should look similar to this...

This of course is a Vulture but pretty much the same.

[aaron78viper]

thanks hippie. i do realize that the stringer needs to come out.. i need to either support the trailer or build a jog like proprider. i am leaning towards the jig and working on the trailer in the meantime, its still a roller i know i know it needs to be changed

[aaron78viper]

im getting close to make an order for some core materials, and I realize balsa is a quality core. Here is the dilemma: (from express composites) I calculated 6 ft wide x 15ft long is the hull as a rectangle(I should have more than enough I know) 90sq.ft. is the goal for surface area here

1/2" balsa comes in 2'x4' sections for $25.. (or 8 sq. ft.) making $3.13/sq.ft. therefore I need 12 sheets, making 96 sq. ft. 96x $3.13/sq.ft. = $300

Another option is the honeycomb polypropylene:
1/2" honeycomb in 4x8 ft sections for $59.58/sheet..(one sheet is 32sq.ft.) making $1.86/sq.ft. therefore I need 3 sheets to make 96sq ft. 96sq.ft.x$1.86 =$178.56

now that I see balsa is not as cheap as I thought, AND, express states honeycomb is preferred throughout the world in marine applications... Does anyone know, why shouldn't I use the honeycomb core available? I may need to call them and discuss it, but I want to know why you guys didn't do it. I tried to show my math the best I could. School is in session, im here to learn guys

[Hippie459MN]

I am looking at that now also and I dont see why you couldnt. Unless its not very flexible for following the contour of the hull like you can with bulsa. I would give Tomas or anyone else a call over at Express and talk to them. Oh yeah, Tell em you head about them from here. They know about us guys here very well. Let us know what they say. Its certainly an option for when I do this again.

[aaron78viper]

I finally got to do a solid days work today, cut out the air box, which was hiding the worst of the rotten core. Apparently, hydrostream did a poor job on my pad area from front to back, super dry glass work, nearly seethrough mesh. Even under the balsa was unsaturated sheets of glass pulling out. I am shocked it never delaminated.