Bell Composite Hull Flattening???

Advice
#1

I have seen people refer to the fact that some of the Bell solo hulls have a flattening effect when removed from the mold. I recall this was associated with certain layups in particular and think it was only mentioned with the Merlin II. Not sure about the Magic and Wildfire/YS.



Can someone please elaborate on which models / layups this happened with and why?



thanks



Matt

#2

Mine did
due to the placement of a flat panel of foam rather than a molded panel of foam. The foam was not molded to fit the canoe, rather just forced in.



Merlin II. UL layup. An older model. Black Gold did not have the foam panel.



Aluminum gunwales werent prebent either. That also decreases rocker.



Sometimes the outfitting of the hull after its out of the mold is important.

#3

Speaking of the outfitting after the
hull is completed, those who favor or can tolerate a foam pedestal seat can stuff that between the center thwart and the bottom and actually push the bottom down a bit. Did in on a Tripper and got the hottest pivoting Tripper ever seen.



But it might not reverse the effect of a flat sandwhich.



I’d suggest playing with the effects of the slight flattening. It might make a canoe ferry much better across strong currents.

#4

…
Where’s CEW when we need him??

#5

I think he is tired of answering the

– Last Updated: Apr-06-10 1:47 AM EST –

same question.

Not that I am any good at the search function either. Sometimes its darn uncooperative.

He just might....be paddling!

If we keep bouncing the post..maybe he will notice..how long can we do this?

#6

Paging CEW…
NM

#7

Best answer for you
is to call the companies you are looking at and ask them if they preform the foam insert to the mold shape before lamination or if they use a flat foam sheet.

#8

Bell and other bottoms

– Last Updated: Apr-06-10 6:48 PM EST –

In the mid 90's we noticed that the all fabric Black/Gold hulls had rounder bottoms than the White/Gold laminates that had core mat bottoms. We hypothesized that the heat of all that resin curing caused the variance.

Then we started doing foam cores. While we designed a foam oven it was never built; the cores were dropped in cold and formed to fit the hull by vacuum pressure. Again the bottoms were flatter; either due to the foam rebounding or, again excess heat when the thick resin putty under the core cured.

Fixes seem to be preforming the foam or, in the case of leading edge infused hulls, using scored foam that conforms to the hull shape and also eliminates the resin pool under wet bagged cores.

Then there is the rail situation. I designed the two piece rail system in Lake Placid and, while I wrote the protocol for installation and designed roller systems for pre-bending, had never done same until I re-railed Kim's Merlin II last summer. Unless aluminum rails are pre-bent to match shear width curvature they will drop the stems and flatten the bottom too.

These issues are not unique to Bell. The same things occur when other builders use core mat and, maybe, SphereTex, fail to preform foam cores, use excessive resin under cores or apply aluminum rails without pre-bending.

So there you have it, again.