GD&T for Teak wood

[MrAndersson]

Hello,
I would like to know if there is a tolerance defined for teak wood for boats.

A teak standard is 40 mm id from the caulk line to the other caulk line. A caulk line is 5 mm wide.

A margin width is 60 mm.

What would be an acceptable tolerance for these dimensions. Has this been determined by the American National Standards Institute?

Any help is greatly appreciated.

Thank you,

Kevin

 

[Zapster]

What would be an acceptable tolerance for these dimensions?

Anything you want; however, there is a cost associated with tight tolerance.

Is the boat in a controlled environment?

 

[MrAndersson]

The decks are all done before they are installed on the boats. The first part is to create a template of the deck, take the template and then create the teak decks.

There are several tolerances I have to work with but none are defined.

The first one is the tolerance with the template.

I was thinking of an 1/8" maybe, but my educated guess would be based on what? Something production can handle and the customer accepts?

A teak deck is not a rocket ship or a critical part of a boat. Plain esthetics, but production must bear in mind for QA/QC approvals.

I would like to base the Tolerance on something better than "because I say so"

 

[MintJulep]

Notice that the root of tolerance is "tolerate".

The purpose of tolerances is to define how much variation from the ideal nominal dimension can be tolerated before the part no longer works as intended. As such it is a design function to determine them. The concept of a standards body such as ANSI being able to define a standard tolerance for anything is ludicrous; how could ANSI possibly know what you are building or how?

How big is the deck? How is it attached to the hull? What is the variation from boat to boat in the finished hull dimension? How stable are the deck and hull dimensions as temperature and humidity change?

Only the designer knows these things.

 

[pso311]

You need to to determine the swell/shrink of each board due to moisture content, and design the deck such that this can occur.

The listed value for Teak wood swelling parallel to the grain is 2.2% of the green dimension, and perpendicular to the grain 4.0%, and these values suggest that Teak is a good choice for your application. (page 74 Hoadley)

For further reading: "Understanding Wood-A craftsman's guide to wood technology". R.Bruce Hoadley

This is the best book I've seen for explaining wood in more of an engineering sense.

-Scott