Why not balsa?

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: Why not balsa?

I've been reading a-lot of posts over the last six months and have noticed nobody uses this. Instead opting for ply but why? I use to work in a FRP plant, we would make everything from yellow iron parts up to nacelles for wind energy (that's the part which houses the motor and such). These same parts would be in the elements 24/7 and under a-lot stress and I mean a-lot. We used to encase a lot of metal brackets or more accurately called stiffeners but never ply. The cost and weight ratio was always a problem. I always wanted to ask that question when I worked there, but all the old timers where either retired or dead from the era when they used to make boats. Any ideas?:confused:

Regards




Most of the boats being discussed here are relatively small and were built to a price point, plywood offered a low cost, readily available and easy to work with product that was also more durable than Balsa. Plus while the plywood was used for a core, it also supplied strength itself even without glass, so it was more versatile. Transom skins could be fairly thin and still hold up well, and the plywood floor only needed glass so it could be waterproof, not really for the strength the glass added.

Balsa adds cost by increasing the number of steps needed to make the boat, plus more training is needed to use it correctly and on these small boats there were limited areas where it could be of any great benefit.

When these boats are being re-done the easiest method is to stick fairly close to the original design and products used, because for the most part they worked well, the biggest shortcoming was workmanship in the production plant.
 

sasto

Captain
Joined
Jun 1, 2010
Messages
3,918
Re: Why not balsa?

Most of the boats being discussed here are relatively small and were built to a price point, plywood offered a low cost, readily available and easy to work with product that was also more durable than Balsa. Plus while the plywood was used for a core, it also supplied strength itself even without glass, so it was more versatile. Transom skins could be fairly thin and still hold up well, and the plywood floor only needed glass so it could be waterproof, not really for the strength the glass added.

Balsa adds cost by increasing the number of steps needed to make the boat, plus more training is needed to use it correctly and on these small boats there were limited areas where it could be of any great benefit.

When these boats are being re-done the easiest method is to stick fairly close to the original design and products used, because for the most part they worked well, the biggest shortcoming was workmanship in the production plant.

I don't know much about restore, but I'm currently doing one.....I have worked for many boatbuilders though, and I couldn't agree more with you..ondarvr
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: Why not balsa?

Prepreg what? Carbon? If so, why wouldn't you use an advanced core? Here is where all the confusion comes from. Are you talking about a FRP panel, or a small part? Building a hollow part such as a bike frame from autoclaved prepreg carbon is waaaaaaaay beyond the scope of pretty much anything on this site. Most of the folk here scratch their heads a bit trying to understand why balsa is used in boats, let alone prepreg carbon. I don't know what your background is, but a cored panel is going to be far lighter than a solid FRP layup at an equal level of strength. Solid glass boats are durable yes, but extremely overweight and poor performance is the result.

Prepreg base kevlar. Didnt need an advanced core due to size. It was a mid 30' custom fish not panels but whole boat hull..stringers..deck center console all prepreg. ( dont know anything about no autoclave prepreg bikes ).

Solid glass...and not overweight for its design or power.

Your right about not knowing my backround :) . Ditto m8..

YD.
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: Why not balsa?

I read that cause you said that...

Now if you mean to say that's not exactly want you meant then that's one thing, but You said that it is "just very expensive using glass" as in all glass as opposed to building with a core.

Feel free to explain yourself but stating that you didn't post something so out there makes no sense at all.

But saying "You didnt read that as I never said that core was for cost.." is just out there because that is what you said. "it's JUST EXPENSIVE.... instead of using core"

I read it, you typed it. It pretty much is the entire point of your post.

Man you post some crazy things on this forum which is really out there what with being a self professed yacht doctor.

I mean for real there are some people on here that are real close to being experts and they don't claim it but you do and some of your posts don't back up that claim even remotely.

How about you take it down a notch.

Im not the most verbal/type gymnastics guy in the world..I agree sometimes YOU may not interperate my post the way I posted ( I dont need a type lashing from you saying " What? Are you seriously stating that they use cores for cost?

I can't believe I just read that!" ) cant you just ask for clarification ?

I was just saying boats can build within weight and strength without any core ( size of cource .. I know I didnt stipulate that..sorry ).

Sea ray kinda did it with its 5 series ( I think it was the 5 ) basically 3 peices of wood on a FRP boat.

So If agreed that a frp boat can be made without core ( within weight/strenght params for the size and power ) would be more expensive then a cored then Thats what I was suggestiing.

I never said anything about THEY use to cut cost..nor that its better or heavier..or ANYthing other than simply put that a BOAT can be built without any core..just more expensive.

Peace out..

YD.
 

barbosam

Petty Officer 2nd Class
Joined
Aug 25, 2009
Messages
153
Re: Why not balsa?

Thank you Ondarvr! Finaly a post that's relevant to the original posters question. You have added some clear and simple information and have summed up what we were all trying to say before we were rudely interrupted and sent off course.

Thank you!
 

Shife

Chief Petty Officer
Joined
Oct 22, 2009
Messages
404
Re: Why not balsa?

Prepreg base kevlar. Didnt need an advanced core due to size. It was a mid 30' custom fish not panels but whole boat hull..stringers..deck center console all prepreg. ( dont know anything about no autoclave prepreg bikes ).

Solid glass...and not overweight for its design or power.

Your right about not knowing my backround :) . Ditto m8..

YD.

Ok.. so nothing exciting. Pre-impregnated aramid is pretty generic these days. The boat you describe was built like a brick sh%$house with little thought given to fuel economy and performance. That same boat could have been built using a cored hull and had huge savings in weight with equal strength. If I was having a custom 30+ft center console fish slayer built and the NA suggested a solid laminate hull, I'd fire the NA and find someone with some skill. I'm struggling to understand why someone would spend that much on a bagged and autoclaved kevlar boat and not have weight savings as a priority. Very little was gained over a solid glass layup in this boat you describe. It just doesn't make sense. A large increase in cost for virtually no benefit.
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: Why not balsa?

Ok.. so nothing exciting. Pre-impregnated aramid is pretty generic these days. The boat you describe was built like a brick sh%$house with little thought given to fuel economy and performance. That same boat could have been built using a cored hull and had huge savings in weight with equal strength. If I was having a custom 30+ft center console fish slayer built and the NA suggested a solid laminate hull, I'd fire the NA and find someone with some skill. I'm struggling to understand why someone would spend that much on a bagged and autoclaved kevlar boat and not have weight savings as a priority. Very little was gained over a solid glass layup in this boat you describe. It just doesn't make sense. A large increase in cost for virtually no benefit.

I think there is one for sale now m8.. can you afford this ?

http://www.boattrader.com/listing/2004-Revenge-Yachts-Revenge-LT-Center-Console-97298785

Doesnt make any sense ?

Lookies..

http://www.rvgac.com/About/Hist_main.htm

I think they have moved on since Ive been there...

Im pretty sure they have ... ( too bad my mom got ill and I had to leave when They had there Small Shop ) ..

I was a part of that group ( count them 10 ! ) that pregged the molds and the parts ( the Plugs came to us using a 3rd party 8pt router foam built and Duratecked Plug ).

So..again.. you can build without wood .. you just need someone like the DOD to Buy it.. unless you have a hundred K to get one of there small mods USED ;).

YD.

PS. GOBBS of money and Time went into that Fish Slayer .....
PSS. Its One hell of a fish slayer man :) .
PSSS. Those guys were some Smart cookies..
PSSSS. do a 24 hr shift on work and bake..then come back 4 hrs later and pull it ... I doubt you even have a clue what my backround is untill you have to do something like that ....
PSSSSS. Ive got pics :) do YOU ?

Peace Out.
 

proshadetree

Lieutenant Commander
Joined
Jul 19, 2008
Messages
1,887
Re: Why not balsa?

Yacht Dr I have pics but last time I posted them I got banned. Cant we all just get along? :D Those rides are way over what my big hinney has ever been in. You sure have worked on some cool stuff. If you all stop fighting I will re-post my speedo pics, Even though some people might have thrown up a little in the back of their throat :eek:
 

NSBCraig

Lieutenant Commander
Joined
Aug 21, 2007
Messages
1,907
Re: Why not balsa?

YD both links you just posted are cored hulls.

"Epoxy/kevlar hullCorecell hull, deck, and lid and hatches"

"The composites were fully cored using Airex? core"
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: Why not balsa?

Yacht Dr I have pics but last time I posted them I got banned. Cant we all just get along? :D Those rides are way over what my big hinney has ever been in. You sure have worked on some cool stuff. If you all stop fighting I will re-post my speedo pics, Even though some people might have thrown up a little in the back of their throat :eek:

I wanna see the speedo pics :) ( as long as its boat related and not swimming wear ;) ).

Im all for getting along too :)

As for the past .. let say argumentitive sake.. Ill say.. OK.. MY bad..sorry ( I had thought the first off was a no core boat..I must have been mistaken.. you know how it is with us old timers :D ) .

YD.

PS. how do you do the Bulgy eye thingy with the smilys ?
 

Shife

Chief Petty Officer
Joined
Oct 22, 2009
Messages
404
Re: Why not balsa?

YD both links you just posted are cored hulls.

"Epoxy/kevlar hullCorecell hull, deck, and lid and hatches"

"The composites were fully cored using Airex? core"

I think by now it's obvious that the Dr. is either pulling our chain or doesn't know what the heck he's talking about.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,072
Re: Why not balsa?

ENOUGH!

You have acted like children armed with keyboards.

I will publicly warn everyone. NO MORE ATTACKS ON EACH OTHER.

Do not force my hand.

This post has gotten way off path.
 

proshadetree

Lieutenant Commander
Joined
Jul 19, 2008
Messages
1,887
Re: Why not balsa?

Im sorry but in the past YD has had a great sense of humor. From what he has written I know this man either knows how to search The Google like President Bush or has at least been doing boats for a while.Shife I have not had the pleasure of messing with yet so I did not want to pick on him YET . I think as adults we all realize that regardless what very helpful information is posted we all do it our way in the end which might have been influenced by the opinions of the board. The funny eyed face is on the right hand of your screen when you post:eek: And the the pics of me in my speedo were banned from the internet because it was thought to cause violent stomach spasms and vomiting:D Go figure Im a sexy beast.:confused:
 
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