Boat Building Forum

Find advice on all aspects of building your own kayak, canoe or any lightweight boats

Re: Strip: Best sanding practices
By:Rob Macks/Laughing Loon CC&K
Date: 2/27/2012, 11:08 am
In Response To: Re: Strip: Best sanding practices (Mike Bielski)

: You can't get a good finish without hand sanding. I like sanding,
: and having experience professionally spraying- it's all in the
: prep work. Long and flat surfaces look really bad to me when
: they're wavy,

: If it were true that the act of building a strip boat produced a
: fair shape, we wouldn't need to sand at all...

: Having done auto body work, I can tell you that even on a strip
: boat I can tell if it's only been sanded with a ROS and not a
: long board.

: m

:Yep, long board makes a world of a difference on a boat, ROS is a great tool, but it's contact surface is too small to even out the surface. I'm sure Rob's stripping results :in a very fair surface that then allows him to only use the ROS, but not all have the same stripping skills as Rob so the long board is more important for them to get the :surface truely fair.

:Bill H.

:With three sixteenths strip thickness there is not much leeway for error. Real fairing, in the traditional sense, could leave one with very little wood in places, unless the :accuracy is there to start with.

:Anyone who is new enough to make an unfair strip boat is, I think, unlikely to be able to do a proper fairing job anyway.

:I never felt the need to fair a strip boat. Sure there may be areas that are not 100%, but I have never been able to find them they are so minute.

:I think the biggest cause of small dips is probably overworking small areas in an effort to eradicate perceived blemishes. If one keeps the ROS moving over a large enough :area without defining boundaries in the process and just continues until it is all uniform it should be enough.

:Etienne Muller

I'm trying to share information to to make building easier.
These are subtle points I'm trying to convey.

Approach and attitude can make all the difference in whether building is hell or fun.

Strips can naturally produce fair curves. Take advantage of this by making strip alignment your highest priority!

3/16" thick strips are more flexible and are easier to align and twist than 1/4" thick strips, especially with the aid of the heat gun.

The perceived advantage of using a thicker strip ensures you will need the extra thickness to correct the problems thicker strips create.

The strips are the foundation of your boat. If the strips aren't aligned and don't remain in contact with the stations and stems
every following step in building, will be to correct the problems of that foundation.

Fixing problems is always harder and more time consuming than getting it right in the first place.

So, if you realize the strips naturally create a fair surface and you focus your work to allow this to happen the result will be most
likely to produce as close to a fair hull as possible. This will reduce the work of every following step.

The random orbital sander (ROS) deserves the same respect as other tools such as the hand plane or chisel. By that, I mean it has the same
requirement of understanding it's use to maximize it's design potential.

As an example. A novice using a chisel right off the store shelf might use it with a hammer to get their expected results on a hunk of wood.

Whereas, an experienced woodworker understands he/she must sharpen a new bladed tool. They must have the skills to know how to sharpen and KNOW
what a sharp tool feels like. They know how to hold the tool and that a bladed tool slices smoothly through wood with hand pressure when the blade edge
is skewed to the direction of cut.

A novice, and unfortunately a lot of experienced woodworkers don't realize the ROS requires the same level of thought and training to achieve the quality
of workmanship possible from this tool. Perhaps this may be in part, because there are more choices and more variables available when using a ROS.

You must sharpen a bladed tool. You must choose a sandpaper grit for the ROS. But first, you must know which backing pad to use with the sandpaper.

For a flat or convex surface a hard backing pad is necessary to produce a flat fair surface. Grit choice is like setting the depth of your plane. And if you don't
know when the sandpaper is dull, just like when a bladed tool is dull, you will do more damage than good. The speed control of the ROS allows increased subtly
of cutting.

As important as skewing a bladed to for a smooth cut, holding the ROS pad flat against the wood surface is crucial to understanding how this tool excels
at producing a flat fair surface. Along with holding the full sandpaper as flat against the wood as possible, light pressure allows the disk speed to remain
high which cuts most aggressively, AND light pressure follows the surface without creating the waves characteristic of heavy pressure used with incorrect
sandpaper grit. Finally moving a ROS in a linear fashion will also contribute to an irregular surface especially on the curved hull or deck of a boat.
Circular strokes will follow and reinforce curved surfaces and produce the most fair results.

Consider the ROS with the same respect woodworkers ascribe to tools such as the chisel or plane, and realize, with understanding
and skill, it has the ability to produce a nearly perfect fair hull.

Am I saying, no hand sanding or fairing will be required? That will depend on your skills with stripping and ROS sanding and the level of
mirror surface you want.

What I am saying is that if you focus on stripping and learn to use a ROS to it's potential, you will have MUCH LESS WORK in every other part of the project!

So yes, it's pretty obvious, when someone uses a dull chisel and a hammer to butcher a piece of wood. An experienced woodworker will say, wait a minute
you're missing something.

What's not so obvious it that a great many experienced woodworkers don't understand that achieving the best results from a ROS takes
the same patience to learn how and what this tool can do.

A small thing, like learning to skew a chisel blade, has big results, making woodworking easier and more fun.

The same is true in knowing how to strip a fair hull and how to keep it fair by understanding how to best use a ROS.

I hope this helps.

Rob

PS - I really appreciate the opportunity to discuss ideas and techniques on this BB, because it forces me the have to think through what I do
routinely and try to explain it clearly. This is what a teacher must do.

Messages In This Thread

Strip: Best sanding practices
Robert l -- 2/24/2012, 12:03 am
Re: Strip: Best sanding practices
Jon Mortimer -- 2/24/2012, 6:39 am
Re: Strip: Best sanding practices
Rob Macks/Laughing Loon CC&K -- 2/24/2012, 9:13 am
Re: Strip: Best sanding practices
Etienne Muller -- 2/24/2012, 7:07 am
Re: Strip: Best sanding practices
Eric Mattison -- 2/24/2012, 7:26 pm
Re: Strip: Best sanding practices
Mike Bielski -- 2/25/2012, 2:20 am
Re: Strip: Best sanding practices
Rob Macks/Laughing Loon CC&K -- 2/25/2012, 9:21 am
Re: Strip: Best sanding practices
Mike Bielski -- 2/25/2012, 12:54 pm
Re: Strip: Best sanding practices
Bill Hamm -- 2/26/2012, 1:10 am
Re: Strip: Best sanding practices
Etienne Muller -- 2/26/2012, 6:05 am
Re: Strip: Best sanding practices
Mike Bielski -- 2/26/2012, 8:58 am
Re: Strip: Best sanding practices
ancient kayaker -- 2/26/2012, 12:46 pm
Re: Strip: Best sanding practices
Etienne Muller -- 2/26/2012, 1:10 pm
Re: Strip: Best sanding practices
Bill Hamm -- 2/27/2012, 2:05 am
Re: Strip: Best sanding practices
Mike Bielski -- 2/27/2012, 10:49 am
Re: Strip: Best sanding practices
Bill Hamm -- 2/28/2012, 1:37 am
Re: Strip: Best sanding practices
Mike Bielski -- 2/28/2012, 1:47 pm
Re: Strip: Best sanding practices
Etienne Muller -- 2/28/2012, 1:51 pm
Re: Strip: Best sanding practices
Justin -- 2/29/2012, 5:29 am
Re: Strip: Best sanding practices
Kirk Fredericks -- 2/29/2012, 5:22 pm
Re: Strip: Best sanding practices
ancient kayaker -- 2/27/2012, 11:16 pm
Re: Strip: Best sanding practices
dave g -- 2/28/2012, 12:42 am
Re: Strip: Best sanding practices
ancient kayaker -- 2/28/2012, 10:37 am
Re: Strip: Best sanding practices
Bill Hamm -- 2/28/2012, 1:40 am
Re: Strip: Best sanding practices
george jung -- 2/28/2012, 12:01 pm
Re: Strip: Best sanding practices
Bill Hamm -- 2/29/2012, 1:48 am
Re: Strip: Best sanding practices
John Abercrombie -- 2/28/2012, 3:48 am
Re: Strip: Best sanding practices
Rob Macks/Laughing Loon CC&K -- 2/27/2012, 11:08 am
Re: Strip: Best sanding practices
John Abercrombie -- 2/27/2012, 1:03 pm
Re: Strip: Best sanding practices
Rob Macks/Laughing Loon CC&K -- 2/28/2012, 4:15 pm
Re: Strip: Best sanding practices
dave g -- 2/27/2012, 10:41 pm
Re: Strip: Best sanding practices
Dan Caouette (CSFW) -- 2/27/2012, 11:55 am
Re: Strip: Best sanding practices
Mike Bielski -- 2/27/2012, 7:56 pm
Re: Strip: Best sanding practices
dave g -- 2/27/2012, 10:09 pm
Re: Strip: Best sanding practices
Bill Hamm -- 2/27/2012, 2:02 am
Re: Strip: Best sanding practices
Scott Fitzgerrell -- 2/27/2012, 11:56 am
Re: Strip: Best sanding practices
Ian Johnson -- 2/26/2012, 6:37 pm