question re finish

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obd
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question re finish

Post by obd » Tue Nov 27, 2018 8:28 pm

A question for those who have veneered and finished bright. Is it reasonable to assume that extra coats of epoxy can be used to build up minor flat spots in the veneer? I was planning on 3 coats of epoxy prior to the 2 part poly but, in some places, some extra coats might optimize "fairness'. Everything looks fine from 10 feet away but close-up I have a few shallow areas. Thanks. Bob

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billy c
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Re: question re finish

Post by billy c » Tue Nov 27, 2018 8:47 pm

Bob-
That would be the only way to fair the hull other than maybe risking sand thru of a thin veneer. The 2 part finishes are very thin and would not be in any way helpful in leveling the surface.
Billy
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Roberta
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Re: question re finish

Post by Roberta » Wed Nov 28, 2018 6:44 am

The best way to a flat finish would have been to make sure the sub structure was flat, or level, to begin with and limiting the sanding of the veneer and deck boards to just breaking the crown to the radius of the deck crown or other area. Power sanding generally creates digs and ruts in the surfaces resulting in dips and high spots if care not exercised. These are amplified when the finish is glossy. Long boarding by hand is the best method to achieving that really level surface when the glossy coatings are applied.

My point is, it isn't a great idea to be fairing and leveling the surfaces with paint or filler coats. If you are forced to do this for fear of sanding through thin veneers, get a good flexible longboard of at least 24" long and sand each coat until you are starting to break through the coating in the high areas. Then recoat and re-sand until all the low spots are filled in. Refrain from using power tools in this process. Due to yellowing and darkening of subsequent coatings, there may be shading variations in finishes that required too much fill in low areas. Sometimes removing some wood on the high spots is necessary, but care is needed not to sand through to substrates.

Bottom line is, a truly level surface that lends well to those glossy coatings that look like the hood of a show car begins when the keel is laid.

Hope this helps,

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

TomB
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Re: question re finish

Post by TomB » Wed Nov 28, 2018 8:16 am

Bob,

I used an air file and 6" RO sander to fair the hull and the "scribble" method to get a flat hull, scribbled all over the hull with a pencil and when the marks JUST sanded off with a long board I figured I was there...

I applied three coats of epoxy and it looked great, nice and flat. Then I used a long board to scratch the shinny epoxy and remove sags and orange peel...That's when a number of low spots appeared (RO sander resting too long in one spot). :shock: :shock: :shock:

I flattened again with a long board going through three coats of epoxy in two spots and still had eight or ten low spots. Another coat of epoxy was enough to fill the low spots but still left the need to sand off the shine, sags and orange peel for confirmation. I am now applying more coats which will be sanded...again. So I will wind up with high spots getting three coats of epoxy and low spots getting four or five coats. I defer to Billy and Roberta to predict the long term appearance problems, no question uniform is better.

In hind sight: I should have sanded the hull one more time before the first coat of epoxy; I should have sanded the hull after the first coat of epoxy.

Tom

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