polyurthane during the building process? - Woodworking Talk

btyirin · 11-22-2008, 12:41 AM

Hey guys. This is going to be hard to explain but I just thought of it now and wanted some input for the forum. If you look the table in my photo album or have read my post about leveling the inlays on it with out going through the veneer this will make a lot more sense.

Anyway. I'm working on another round table very similair to that one but with more inlays. I had this thought that I could go ahead and put the poly on the oak sections BEFORE ever cutting the grooves for the inlays. I thought this would serve two purposes.

1) to help protect the wood while messing around with inlays.
2) it might be a lot easier to sand the inlays down flush with no worry of going through the veneer. Or at least a really good indicator that I am starting to go through.

But once its all done will I be able to get a nice good even finish on it? Is this possible?

Brian

Teenagewoodworker · 11-22-2008, 08:26 AM

ya i have done that any you can do that. what i did is just the holes to receive the inlays first then you can use poly but i don't think you need too. trim the inlays with a gooseneck chisel and then you can hand sand until flush. hand sanding it will be very hard to go through your veneer.

clockdaddy · 11-22-2008, 11:48 AM

Your idea is great, but there are a couple of things to watch for. I'd certainly try it first with some scrap wood to see if it will meet your standards!
Keep in mind that no saw blade or router will leave the ridges of the cut area for the inlay perfectly smooth. There are minute chips along the small ridges.
When sanding the inlay after insertion, you'll also sand some of the finished area. The new inlaid area; the sanded area on the finish; and the area previously coated with finish, offer different absorbsion rates. Additionally the surfaces of the finished wood; the sanded area and the raw wood area will come out with a different appearance when finish is applied. Additional coats of finish with sanding between coats, should make the appearance those surfaceslook more even.
It's kinda a trade off. You protect the surface of the veneer, but you have to spend more time and effort with the finishing.

CD

mics_54 · 11-22-2008, 12:36 PM

my thoughts:

I can see the dilema and the only solution that I can think of is extremely accurate insertion of these inlays to minimize sanding. I have never had much luck for instance repairing a ding or blemish in finished wood and having the new area blend perfectly with the old because as clockdaddy stated the absorbsion rates of the wood change with sanding.
How do you create your inlays?

btyirin · 11-22-2008, 04:44 PM

Thanks guys. the straight inlays are ripped on the table saw. The curved ones are from a router jig and then ripped. On this next table I am going to use my inlay jig for the router. The brass one that rockler sells.

I'm planning on making the inlays a bit proud and then making a jig for my router to level them perfectly with the surrounding veneer. So I';m thinking that if I spend some serious time on the jig and practice a ton of patience I won't have to sand that much.

But after reading your thoughts on the finish and the absorbtion rates. I think I'll pass and just take extra care. I'm still learning how to lay a good finish.

I'll mention this though. Last time I did that table. The oak venner got a little dirty. You know how tools and especially aliuminum can get your hands all blackened up. Bring the open grained wood that oak is I think I'll wear some latex gloves this time do avoid rubbing dirt and crap into the wood. It's going to take a bout week to do these inlays.

This is what I'm shooting for (pic below) I might change my mind though. Basically its the same table I built before but with the tengwar symbols added. I had just gotten done glueing up the oak sections and a little piece of veneer ripped off because I had forgotten to use a plastic bag between the clamping faces to protect against glue. So I needed a solution to cover up the void. I like the tengwar symbols. The trancription means "Table of Friends" Not that many people would take the time to figure out what it said. I guess I could put anything there........but might has well be something real. Well, sort of real. It is a fictional writing language. I always thought it looked really cool in the Lord of the Rings movies.

Last time I used mimwax semi gloss. Since then I have learned that you can't really rub out a semi gloss due to the stuff they put in there do make a semi gloss. So this time I guess I need to use a full gloss poly? And then I can rub it out to whatever I want. I don't know if that makes a difference in what we are trying to figure out or not.

So far it sounds like the safest way is to just take great care and wait to put on a full finish at the end

clockdaddy · 11-22-2008, 05:59 PM

Sounds like good solid thinking to me!
One little trick I learned many years ago is to mark the veneer with the side of a pencil lead. Just scribble all along the edge. Anything left is easily removed.
As you are sanding, the marking on the veneer will let you know when you get over on the veneered area. Obviously, the more you sand on the veneer, the lighter the pencil make becomes.
While not being the absolute solution to the problem of over sanding, it's certainly a good guide.

CD