Uncle Dave

I see SB-100 but I dont see D-100- are they they same?

Is there a corecell test series available in any testing format you approve of? I dont see one when I go to gurit.


UD

Steve 1

Testing That would be from Gurit or Gougeon Bros The balsa sheets had a "D" Prefix there was no scrim on this material the blocks were all glued together.

I have always used the drop hammer results and was setting one up when I went overseas as it is more in line with the slamming loads,which are very mechanical like in nature and represents the ultimate trial!

AIR TIME

whats the average cost of the 54 over a mil? and are they covered in glass on the out side ? I just looked quick at 2am last night, built by eye with a jig correct that they use to start them it looks. awesome looking like a BD SF with the flared deck.

AIR TIME

Steve do you have any pics of the last boat you did and year to show uncle dave and me are you saying the foam flexes where the balsa doesn't. if so wouldn't a bottom made out of core and gel crack the stiff gel coat or paint in rough water or is it you have a skeleton ribbed frame the core attaches to. if I remember right your boats have a skeleton like frame jig?? thanks art

Steve 1

No wrong when hit HARD HARD it will yield OR transfer the loading to a larger portion of thi inside lamnate .where The Balsa will Fail! How do you read cracking Gelcoat into that ? So you would rather have a failure instead?

Steve 1

Here is a very old Airex boat.

http://www.youtube.com/watch?v=esxxtLg8qJ4

damdonzi

Somewhat similar boat (first Quad sportsfisherman I've ever seen) but I guess you can envision what it might look like running into a tow cable from this video:

http://www.quadzeus.com/media.html

Uncle Dave

Steve- what the lab tested isnt "my wood". Nor Skaters, Schiada, Sabre, Lavey, Eliminator,Howard etc. etc. etc.

I've never seen non scrimmed balsa used in a core. How would non scrimmed balsa follow the shape of a hull?

We use labs all the time in my industry when they test they always post their name in a lower third on screen and state each manufacturer being tested along with the model number and date of material acquisition.

Ive never seen a Lab use a open locked stanley tape measure as a primary measurement tool.

I found Gurits test data on corecell.

Here are the #'s they post. You guys can all read em.



UD

T2x

Fascinating dialogue........

IMHO this is kind of like chocolate and vanilla...different strokes for different folks. Steve is probably the best foam core based builder around and has proved that over the years. Peter is the best performance boat builder on the planet and likewise has an amazing history.

My take is that foam core is wonderful in low surface impact applications, but repeated ballistic cycles tend to constrict the core. This leads to skin flex ( the natural result of the "bending" that Steve alludes to) and subsequent separation, followed by delamination and failure. Balsa , while certainly not perfect, is a better choice in these conditions. On the other hand, decks, bulkheads and other non impact areas are much better suited for foam core materials. Steve will disagree and certainly provide contradictory data, but if it were my nickle and my boat bottom, I would spec balsa on all running surfaces.

No disrespect intended towards Steve, as I believe he can build a foam cored boat that will withstand much more than most other builders and he is a genius at producing craft which limit impact levels through design and light weight.

T2x

Steve 1

Numbers ?? so what what do they really mean? Here too continue:
Uncle once again you cheap shot the discussion, the testing was done at Sigma Labs . The numbers are just that with the Plastic cores they do not indicate Failure Got it ! only the material moved and that was marked as it's physical VIA the ASTM Methods Now I just prefer the nasty moment of Inerita/Panel Beam Deflection Via any Extreme and Severe loading too be just that and not a Failure Point! Are you with me?? NON scrimmed Balsa LOL Uncle I will do another post.