The back of my slipper chair has 2 support rails. Before I removed the fabric, I could see those rails pushing against the old fabric. The last upholsterer did not add anything between the fabric or the rails. The picture is of the back after fabric was removed, and before tear down was completed.
(https://forum.upholster.com/proxy.php?request=http%3A%2F%2Fi1108.photobucket.com%2Falbums%2Fh403%2Fjajjaaj%2Fchair%2520back.jpg&hash=82ffbe867e511bd8fc4cad5f8d4ce47e) (http://s1108.photobucket.com/user/jajjaaj/media/chair%20back.jpg.html)
The chair back curves and I will add webbing and Dacron, but I'm worried the wood might still show through. What else can I do to make sure they don't, and to give it a nice round look?
The webbing and padding should do it. When I'm doing the outside back on a chair like this I try not to pull the tar out of the webbing. I think it looks stylish and attractive if the fabric bows in ever so slightly.
If your problem is with the outside back (not inside back), I think you can get where you want to be by adding a layer over the outside back, pulling the material fairly tight from top to bottom. Then, over the burlap, you can add a layer of cotton/dacron and even cover over that with a muslin installed with the same general technique as the burlap.
This will then give the final covering plenty of support to prevent frame members from showing through.
Where the burlap/padding (cotton or dacron) is stapled around the edges just use good judgement to not create too much bulk to give a problem when installing the final covering.
This problem you are having is a fairly common issue on some barrel backs.
Don't over do the padding, it shouldn't take a thick layer given the support the burlap and muslin will provide. Just a comment, sometimes the burlap and padding will be enough to accomplish the look you are seeking. The muslin helps and provides extra insurance.
Good luck, looks like it will make a nice chair.
Doyle
You would want to put a strip of webbing close but not covering, on each side of the 2 vertical rails so it gives a good rounded area. Then a layer of under fabric pulled tight top to bottom and just take the slack out side to side. Then a thin layer of dacron or cotton and put the outside back on. Pulling the same way as the under piece.
You may also consider adding a center rail and slightly make all three rails concave. This will make a better balance and even backrest for webbing and padding.
SA
All great ideas! Thank you! Now I feel a little more confident that the back will be smooth and flawless!