Seal coat options

[Joe Vannucci]

Hi, I make art frames to order, in a variety of hardwoods and finishes. Some of the styles have very thin mouldings (3/8" thick), and sizes up to 24x36. I double-mill everything to ensure stability. The larger frames usually get a strainer (supporting frame within a frame) but not always.

The process works well, but I've always applied a finish more or less immediately. Now I'd like to make some frames in advance, to take advantage of some down time, or to maximize the efficiency of a batch run. I'm concerned about stability if I leave the frames raw for a month or more until I receive an order for that size and spec.

Normally I'd just slap on a wash coat of dewaxed shellac to stabilize the wood. This would be fine followed by most of my finishes, but I suspect it's not a good idea to apply shellac (a film finish) under something like Tried & True Oil Varnish (the classic 'in the wood' finish). I fear the shellac, no matter how thin, would block the oil from soaking in as deeply as it normally would. 

Thoughts? Ideas? Thanks in advance.

[Wimayo]

First, be careful about selecting your wood. Make sure it is straight grained and of a stable species.

Second, I'm not sure this will be appropriate for all finishes, but I think that danish oil or similar products, once completely cured, will be compatible with most other finishes; particularly other oil based finishes. It will have some effect on stain penetration, but you should mostly get good results with gel stains over it.

Just a suggestion for something to try as I haven't done it: maybe an exterior waterproof sealer like Thomson's Water Seal would do what you need.

[wtnhighlander]

I would think almost any sealer you apply will affect future application of stain or dye. Best bet is to experiment with a frame or two and see what the result looks like. Alternatively, could you do something like stretch-wrap instead?

 

[Joe Vannucci]

2 hours ago, wtnhighlander said:

I would think almost any sealer you apply will affect future application of stain or dye. Best bet is to experiment with a frame or two and see what the result looks like. Alternatively, could you do something like stretch-wrap instead?

 

That's what I figured. Oh well.

 

Stretch wrap... Hmm, I ship the frames in plastic bags. Maybe I'll just bag them early. It's not air tight, but will definitely minimize environmental changes.

For reference, here are a couple of 20x24 frames in mahogany and walnut, ready to be boxed up. I'd just bag 'em before finishing and tuck them away for later. Then save the bag for later shipping.