Different of Chopper Gun & Manual Laminations

[Felix-Arees]

Is there anyone who can explain to me the different of using a Chopper Gun and Hands Manual Lay-up during lamination of hull.

I have a scantling calculation of this matter and also a section modulus from ABS Rules & Regulations, and i want to make sure that, if there is any problem if i used a chopper gun instead of Hands Manual lay-up for my 40Footer Commercial Boat.

I used to compare the different between sample in my hands now, but please help me to determine all of this matter. Thank you felloes - Arees

[Felix-Arees]

Thanks felloes..more power to all of you!!

[SamSam]

Originally Posted by Felix-Arees

Is there anyone who can explain to me the different of using a Chopper Gun and Hands Manual Lay-up during lamination of hull.

I have a scantling calculation of this matter and also a section modulus from ABS Rules & Regulations, and i want to make sure that, if there is any problem if i used a chopper gun instead of Hands Manual lay-up for my 40Footer Commercial Boat.

I used to compare the different between sample in my hands now, but please help me to determine all of this matter. Thank you felloes - Arees

To begin with a chopper gun only applies a chopped strand (mat) laminate. The difference between chopper gun and hand layup mat is the CG takes skill to get the same resin/fiberglass ratio. It is also harder to get a uniform thickness, or the thickness you want where it should be. If a mat or CG layup is all you use ( no cloth or woven roven) you have the weakest of all fiberglass laminates, and must compensate with extra materials. So you end up with a heavy boat, possibly sluggish and with high fuel consumption. It also uses the most resin which is the weakest and most expensive part of the layup. Although in your case the resin might be REAL inexpensive, it is still the weakest part. A CG is faster than hand layup, but the best use I can see for a CG is to disconnect the chopper part, or use it sparingly, and mainly use the machine to spray catelized resin to wet out hand laid fabrics. Sam

[safewalrus]

$$$$$$$$$$$$

[PAR]

Judging by the nature of your questions, I'd strongly recommend you stick with the scantlings and laminate schedule the designer specified. These are engineered composite structures and unless you have a solid grasp on the concepts, principles, chemistry, physics, methods and techniques, you'd be best advised against changing the laminate schedule. It would appear you're interested in the money savings a chopper layup can provide, but you haven't the skills necessary to make the necessary decisions regarding the design parameters. You have two choices, wing it and hope for the best when you're father from shore then you can swim back to, or hire a professional to recalculate the layup schedule as a chopped strand job, which will produce a weaker, heavier, but possibly slightly less costly boat. It's your call . . .