What can be done to stop sap spotting on spanish cedar?

[Brad McCollum]

I've seen several posts about cleaning the sap spots off with denatured alcohol but nothing about preventing the spotting in the first place. Is there a way to do this? Are there suppliers out there that sell product that doesn't spot? I had to do a refund on a $300 box because of this. Any help would be greatly appreciated.

[Roy Harding]

Two suggestions for you:

1. Heat your wood prior to cutting the joinery. This causes the sap to run out - at which point you can clean it up. A kiln is the best way to do this - but I use my oven set to around 180 (Fahrenheit). An acquaintance of mine swears that putting the wood into a microwave also works - but I can't vouch for that method.

2. Seal your piece with shellac. The sap will still bleed - but it won't stain. It will simply sit on the surface, dry out, and can be wiped away without damage to the piece.

Good luck to you - I also make boxes and humidors, and I feel your pain on the refund.

[Howard Acheson]

Apply a couple of coats of dewaxed shellac. Be sure to use the dewaxed shellac if you plan to use a poly top coat or a waterborne finish. That will generally stop sap seepage.

Also, buy cedar that has been kiln dried. The heat of drying will crystallize the sap preventing it from seeping.

[glenn bradley]

+1 on shellac as a sealer. Cooking the bulk of the sap out will minimize the problem and the addition of shellac will terminate it.

[Brad McCollum]

Thanks for the replies but I have one question. If I seal the wood with something won't that stop the moisture absorbing qualities of the cedar?

[Brad McCollum]

Damage to the box is not a problem. Cigars stick to the sap and tear when moved. That's the big problem.

[Roy Harding]

There are mixed opinions regarding the finishing of the inside of humidors. Some do, some don't. Personally, I don't.

I make my humidors out of hardwood, and then line them with spanish cedar. The lining is anywhere from 1/8" to 1/4" thick - the "oven roasted" method I mentioned above should be enough to extract/dry any sap in cedar this thin.

[Howard Acheson]

>>>> If I seal the wood with something won't that stop the moisture absorbing qualities of the cedar?

Although there is no finish except two part resins that are totally impervious to water vapor transmission, any finish you apply will greatly slow up the penetration of water vapor. Had you mentioned that you were making a humidor, I would not have recommended shellac for the interior. For the humidor to work properly, you should leave the interior unfinished, I think.

You could still use kiln dried wood which as I said above. The heat will crystallize the sap.

[Brad McCollum]

Thanks a bunch for the info guys. I like the idea of cooking the wood before final planning and fitting. Now if I can talk my wife into letting me use her stove. Oh, by the way, 180 degrees for how long?

[Roy Harding]

I get all the cedar lining thicknessed, sanded, and cut to width/length. Wipe them down with acetone or alcohol, and let them thoroughly dry. Then I stack them (with stickers in between) and clamp the stack with C clamps (this prevents warping). Put them in the oven for 4 - 5 hours. That time is for 1/4" thick cedar - use 2 - 3 hours for 1/8".

It should be noted that I live in a place where we have cold winters. Having the oven on for that long is welcome in the winter. I'm not sure how well it would be received in the summer (especially in Tennessee!)

As I stated earlier - I've been told that a microwave also works, but I don't have any details on it. I also know a fella' who uses a 200 degree oven - but that small difference in temperature may be attributable to differences in ovens (my wife claims that our oven is "hotter" than others).

You'll probably have to experiment a little before you get it all worked out to your own satisfaction. Good luck.