Use of wood as core in polyester

[jfblouin]

Hi Rx

I dont want to arguement too but I want to understand and make good choice. For the 6 first month of my project , I was certain that I build a single skin polyester resin FRP boat. In the begin of february, I think to began mold construction in April. But now, I'm stage fright and I want to review all other possibility. I'm not affraid to get out of the majority way and trying new technics but I want a relative good boat. It is why I think of use on of regional ressource (understand white cedar) in my boat. I'm not interessting by a all wood boat for my kind of boat (see my design post Commments wanted on a RBB hull shape ) because for me it is not match with my design. Maybe I wrong. But I want to use wood force?

I dont understand your "top hat", "cap", "crown" notions. I dont have a perfect english.

Can you give me the reference for your boatbuilding magazine.

Thanks for your information.

[dlang]

just one point i have to make. it's not the core material that is adding the strength, but rather the angles that the fiberglass produces as it contorts to the shape of the core material. Those angle are whats producing the strength.

i work on other things non-marine sometimes and I'll core with cardboard. Yes, thick cardboard taken out of a dumpster. it has a nice interior honeycomb shape, it's easy to bend and cut, and it's free. That's right, 'dumpster diving dave'. Laugh all you want.

Make a test in your shop and create core samples. maybe 4" long, fiberglass on both sides. use cardboard in one sample, you'll be suprised. If you have a piece of 6" PVC pipe laying around, bend the cardboard half-round the pipe and glass that shape to a another flat piece of cardboard. Then maybe try a triangle shaped piece of cardboard. You'll find them all to be real strong.

[rxcomposite]

Dlang,

Great idea. When looks are not in the vocabulary, i sometimes use mailing tubes cut in half. When i need larger diameter tube, i use the cardboard tube form remaining after the fiberglass is used.

But of course i use this only on molds. Customer frown on cardboard form when they see one. Saves time though.

[dlang]

Thanks RX. Cardboard is in the 'wood' family, right? Or at least Pulp and Paper family.

jfblouin, creativity will be your solution. Please share your new discoveries.

Thanks.

[cyclops]

J F. Can you do your boating the way I do in the ST. Lawrence ? Sunrise to 11 AM.--- 5 PM to dark. ---- 11 AM to 5 PM is too windy and white caps.

[rxcomposite]

Dland,

Vasoconstrictor? Isnt that what "******" does? No wonder our crew seems to act strange whenever a lady walks in the shop. Hahaha.

Seriously, i did not know that. I should look more deeply into that as it can cause the heart to pump heavily.

Thanks. This forum is great. I pick up info i would not normally know.

Rx

[rxcomposite]

Hi Jf, Dlang,

There are many types of stiffeners. I am attaching an illustration of the types.

Boatbuilders tend to have a preference and they feel very strongly about it.Add to that that there are preform manufacturers, core manufacturers of balsa and foam preforms, and marine plywood. Hence, there are strong arguements about it.

Each has its advantages as to simplicity of materials, ease of construction, durability, and cost.

I am not an authority regarding this matter as i have not tried all types nor evaluated all merits. That is the reason i shy away from reccomending a particular type. I can only give my personal preference.

[jfblouin]

Very interresting.

When I study the possibility of a wood core in my laminate, it is not for reduce weight but for increase toughness of my boat. So I understand that I can do the same thing without the wood to fiberglass bonding problem and without the laying of a core.

I will re-examine my plan with that in mind

Thanks a lot Rx and Dlang

PS Remember that English is not my first Language and this morning it was hard to write good. Try to understand

[jfblouin]

Cyclops

Where has you go?

In Gaspe peninsule:

June 21 Sunrise 04h00 Sunset 21h00
December 21 Sunrise 07h00 Sunset 16h00

But you are true about wind and wave. Many currents and many wind direction make many change in conditions in the same day. The long fletch create often 4 to 6 short waves with white caps. But some days and almost every mornig an evenig we have flat sea.

It is why I want a seaworthy boat

Let me know your route.

[jfblouin]

Do you think that I can replace all my stringer and bulkhead by this kind of stiffeners?

Remember that my project boat is 23 feet (6.7 m) long, 67 inches (1,70 m) hull beam + 16 inches (40 cm ) collars and 2 feet (60 cm) high plus 2 feet (60 cm) collars . image at transom in attachment