# Chopper Gun VS Hand Laid



## TomFL (Oct 2, 2007)

> If You Could Choose between Two simalar boats and one was Hand Laid and One was chopper gun and the price was the same which way would You Go ?                       Dave


Do you mean NEW boats, same price, one hand laid and one chopper gun? 

Or USED boats on the market?

-T


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## noeettica (Sep 23, 2007)

New Boats ;-)


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## Tom_W (Oct 23, 2008)

Hand laid hands down assuming it is material other than mat. 

Chopper guns use shorter strands and layup isn't nearly as strong for the same amount of weight.


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## copperhead (May 30, 2008)

NY Strip steak or hamburger....usually the Strip always wins...

I'm assuming an equal skill ratio for chop vs. hand laid.  Even the best of materials in the wrong hands won't turn out well.

I'll take a great hamburger over a charred to death NY Strip.

But then again, a chop gun has no place in our shop...


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## TomFL (Oct 2, 2007)

> NY Strip steak or hamburger....usually the Strip always wins...
> 
> I'm assuming an equal skill ratio for chop vs. hand laid.  Even the best of materials in the wrong hands won't turn out well.
> 
> ...


I'm still stumped as to how they could both be the same $$??

-T


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## noeettica (Sep 23, 2007)

Tom you Have a PM


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## Brett (Jul 16, 2008)

Build cost the same...1 man operation, hand laid, no machinery = low overhead


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## B.Lee (Apr 29, 2008)

They both have their place in construction. 

I would prefer to not have a full-chop hull, but there are many out there, and depending on the application, can be jsut fine. A little cloth mixed in certainly gives a lot more strength to a lay up though.

I guess my answer would be it depends on the boat. Do Gheenoes use any cloth, or are they all chop? A Contender has little to no chop in the hull lay up. two diferent applications of fiberglass reinforced plastic construction.


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## The_Skiff_Shop (Oct 28, 2008)

> NY Strip steak or hamburger....usually the Strip always wins...
> 
> I'm assuming an equal skill ratio for chop vs. hand laid.  Even the best of materials in the wrong hands won't turn out well.
> 
> ...


Nailed it IMHO [smiley=1-thumbsup3.gif]


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## topnative2 (Feb 22, 2009)

hand laid anytime over chop---all things being equal=== it is stronger


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## East_Cape (Jun 3, 2008)

> If You Could Choose between Two simalar boats and one was Hand Laid and One was chopper gun and the price was the same which way would You Go ?                       Dave


What two boats and what kind of resin? what kind of gel? what kind of glass ( mean ounce ) how thick/mils is the lay-up...
need more info to give an answer ...
Still a lot of room for either to be the winner.
;D


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## aaronshore (Aug 24, 2007)

I used to work in the factory for a sailboat company who built "blue water" rated sailboats. Theyr hulls, decks, and parts were mostly chop, then hand rolled. A little hand laid on reinforced parts, mostly structural.


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## noeettica (Sep 23, 2007)

Thank you east cape I will ask those questions  Dave


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## OSWLD (Apr 20, 2008)

> Do Gheenoes use any cloth, or are they all chop?  A Contender has little to no chop in the hull lay up.  two


Gheenoes are a mix of both. They usually chop in a skin coat then hand lay some roven in, chop a little, then lay some nytec (strength for sitting on the bunks, stringers). then chop over top of that. i couldn't see a boat 100% chopped in being worth much. maybe there's more to it than i know, but just chop wouldn't seem to have much strength to me.


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## JoeWelbourn (Dec 11, 2006)

The key structural difference between hand-laid (not mat clothe that is basically chop fibers rolled up in a sheet) and chop gun is the length of fibers and fiber orientation.  The longer the fiber and the more controlled the orientation, the stronger the object since the longer, strategically-placed fibers  can disperse more energy to other neighboring fibers to distribute the loads/force.  Hence why unidirectional thread in carbon fiber is so strong in one vector and so weak at a 90 degree angle to the same vector.  Same goes for wood, that is why plywood is assembled in plys that alternate the grain (fiber) orientation.  There is a whole science to advance composition lamination schedules (how the reinforcements are oriented).  Not all lay-up schedules or reinforcements are the same eventhough the object may appear identical.  I suggest hand laid is always stronger if the operator knows how to lay fiberglass professionally.

Chop gun is used because it is inexpensive and allows for fast lay up on simple or complex shapes.  

Float Shallower,
Joe


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## copperhead (May 30, 2008)

Without getting into alot of engineering technicalities, simply put a hand laid bi-ax or woven roving laminate will be thinner and weigh less than an equivalent chop laminate of equal tensile strength. The same chop laminate should cost less for the labor component in a production environment. Thus a chop production boat should cost less to produce while being heavier. 
Its all a compromise, isn't it?


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## GJBenn85 (Jan 30, 2009)

A little off topic here but quite a few boat builders claim to only use chopped glass as the first layer in the layup because it supposedly creates a smoother bond under the gel coat. Any truth in this?


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## Brett (Jul 16, 2008)

True, also the second layer, to prevent the pattern of the woven fiberglass (3rd layer)
from showing through the gelcoat, when the hull has been completed.


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## pbjeep (Feb 14, 2009)

If your talking spray chopped gun roving you also have the risk that the resin/catalyst ratio is not correct causing the composite part to either be resin lean or resin rich or not curing at all. Hand lay-up by the right person will produce a better part and tend to get the right resin to fiber ratio and the right resin to catalyst ratio as well

Manufactures use a chopped strand mat between the gel coat and the bulk laminate for several reasons. 1. it tends to show less print through (woven roven pattern showing through the gel coat) 2. Mat, once sanded tends to bite better to other materials like bi axial or woven roven for secondary bonding. But mat does absorb alot of resin creating extra wieght.

Scratch all of that  Brett beat me to it


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## B.Lee (Apr 29, 2008)

So, to bring this full circle, what two boats are we talking about? Or was this just meant to be a conversation about lamiation?


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## copperhead (May 30, 2008)

Not sure what is meant by 'smoother bond'. However, the chop is resin rich and the smooth part is that the thicker chop skin prevents 'print thru', from the next real laminate layer, that's all.

The really good guys, will lay down a thin skin coat with chop (almost like a 3/4 ox mat, very light), let that kick a bit and then hit it again with a heavy chop coat, before a structual laminate. Minimal print thru...


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## pbjeep (Feb 14, 2009)

Mel do yall use 1708 bi ax with the mat side down directly on the gel coat or do yall use the method you just described?


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## noeettica (Sep 23, 2007)

Mr Lee you have A PM ;-)

                                                   Dave

And All the replys are GREAT ! I have learned a LOT Anyone Run a Red "tracer" strand ?


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## copperhead (May 30, 2008)

We skin coat the gelcoat before applying the bi-ax fabrics..


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