TOPIC: white oak "stringers" in core of hydrodyne questio

I'm still at work on the re-core. There are 6 "Stringers" that run from the bow to the transom, which are imbeded in the core. They are made of white oak, however, I can not find anywhere to purchase white oak. So, what wood do you think I should use?...mabie red oak? Anyhow, these "stringers" are not what the floor sits on. Instead, they are part of the core. So, I want to use the best thing!

Thanks for the help

welcome to the site wentworth,try this company,they have just about any wood you would ever need,john
www.kencraftcompany.com/

Hi, I am new on here but maybe able to help. I have quite abit of ruff cut white oak the is various sizes and has been planed and stacked in a shed if you want to drop me a line. I live in CT. Also looking for info on Owens xl19"s if anyone can help.

Do NOT use red oak in a boat. Red oak has NO decay resistance. When using white oak, make sure it is all heartwood. The sapwood of any species, even a decay resistant one like white oak, has no decay resistance.

There should be plenty of saw mills that cut white oak in Pennsylvania. My employer buys tens of thousands Board Feet of all-heartwood white oak for marine applications from a mill in Conover, WV.

Andreas

I'm thinking that when I end up having to do my Glastron, I want to use something other than wood in the stringers and transom so I won't ever have to worry about it rotting again. I know Doug (71 V153) used Tuff Stuff, which I'm having trouble finding any info on, and others recommend Plascore, who does have a website. Anybody have any any thoughts on either of those products?

Hydrodyne made their first boats with side core balsa. Later, they used end grain balsa. From about 1970 on they used balsa with oak stringers. The earlier boats performed well without the stringers, but the stringers were believed to add strength.
Unless you are doing a rebuild for accuracy, I would suggest neither balsa nor oak, as they will eventually fail. If you wish to replace the core with similar core, use a closed cell foam core. It will last much longer than balsa and give better results with adhesion. If you are technical, use corrugated pvc to make a corrugated fiberglass core, then fill the top level with foam and layer on your top layer. this will give superior results but is not technically accurate. However, it is much stronger than any other method and does not add much weight. it is simply not a cost effective method for production boat builders.

If you are forced to continue with balsa, I would eliminate the stringers and build it like the earlier models. I have a end grain balsa 18 skier with a 150 merc v6 on a roller trailer with no problems whatsoever. Use a 1/4 inch thicker balsa if you plan on using a big single or twin engines.

personally, anything one can do to get rid of balsa core to me is a great step in the right direction. I hate balsa core - and am working on replacing a balsa floor hatch on a 2004 boat at this very moment! Eliminate the balsa if you can.

Hope this helps.

great link john. wish i had it years ago. ron

MarkS wrote:

I'm thinking that when I end up having to do my Glastron, I want to use something other than wood in the stringers and transom so I won't ever have to worry about it rotting again. I know Doug (71 V153) used Tuff Stuff, which I'm having trouble finding any info on, and others recommend Plascore, who does have a website. Anybody have any any thoughts on either of those products?

Make up some forms (1 x 6's) and pour your stringers out of Seacast or Nidabond. If had known then what I know now... I'd have poured the stringers in my Fabuglas.
I used regular pine 2x6s coated with Marine Epoxy (Hexion- purchased at fiberglasssite.com) Then, bedded them to the floor with 3M 5200 adhesive/sealer, wrapped them in bi-directional cloth overlapping about 4" onto the floor.

I wouldent mind figuring out a way to use 100% fiberglass. Remember its not what the stringers are made out of, you can use toilet paper rolls but its the shape of the stringer it self wrapped in fiberglass that gives the strength.
Its hard for me to give great advice because im learning too. Im going to have to figure it out myself soon because my g3 is going to get a new set of stringers sometime this year so I too will be working away. I dont want rottin stringers 10 years from now. I may try to use that fiberglass bullet proofing material for my stringers. A bit heavy buy will last, Mike

First, Ab Crosby used hardwood stringers in every boat he built, Crosby and Hydrodyne. I don't know if it was white oak he used, but it wouldn't surprise me. In order to find white oak you're going to need to find a local sawyer. White oak, which is much better than red oak for marine applications, is notorious for cracking and splitting while drying. Hence, most yards don't carry it because of the losses. It is much stonger and rot resistent than red oak if exposed to water. I know I can get white oak in CT and Lake George, NY. Check around...it's there, but not in your typical lumber yard.

Right on Crosbyboat! The difference with Ab Crosby is that he overbuilt everything! The core layup in my 61 Hydrodyne has long grain balsa running bow to transom and is strengthened further with 6 boards of white oak, tapered from 3 1/4 inches wide at the transom to 3/4 inch at the bow. After the core is finished, I will add the true stringers on top to eventually mount the new floor on. I did find a local sawyer who can hook me up, so thanks for the suggestion. I am going to look over what he has. Hopefully, it is heartwood and not sapwood. We'll see.

Thankyou to everyone for the help and suggestions.

Todd

Time to set the record straight. The earliest crosby and SOME hydrodyne boats had NO CORE. Crosby then started experimenting, and found he could reduce the weight of his boats using a dual core balsa, but the cores were side grain. Next, they went to using end grain balsa with and without oak cores depending on the model. But by the late 1960s, most hydrodynes were end grained balsa with oak cores. It was a painful decision, as oak gave the better qualities initially, but when compromised rotted as fast as the balsa. Some boats were built with encapsulated oak stringers. For plenty of pictures go to hydrodyners.com and read throught the forums.
Go here for some core info: www.hydrodyners.com/forum/viewtopic.php?f=2&t=77&p=250&hilit=history+balsa#p250
and here for even more: www.fiberglassics.com/forums/viewtopic.php?f=3&t=2744

I currently have an 18 skier 1967 with the balsa floor now out. There were no stringers, and the floor was end grained balsa.

So, depending on the year and model, you may have any variant.

Hope that clears things up.