Temperature Related Finishing Problem???

[Brian]

So, I've been dealing with Walnut recently and how to finish it.... I've recently moved to where the weather has been very warm; high 90s to 100 degrees F, and probably warmer in the garage. I store all my varnishes, oils, etc indoors where the temp is a nice 78. Now on to the problem....

I've been having a problem with ANY finish I apply to the Walnut immediately turns it black. You name it... Waterlox, Arm-R-Seal, Seal-A-Cell, Linseed Oil, Danish Oil, Tung Oil, Teak Oil, etc. Now, I am applying these finishes in the warm garage. I have no problem with gumming up or anything of that sort, just the blackening of the wood. I'm wondering if 100 degress is simply too HOT to do finishing work? Or is the temperature CHANGE an issue (i.e. taking the finish from a cool storage area and applying it in a warm finishing area without acclimation)?

Now I know that all these products are not bad or contaminated. There's just no way. Some are only a couple weeks old. I've filtered a few just to make sure nothing was suspended, to no avail. And, just a few weeks back I got great results with them on test pieces.. Not the BLACK results I'm suddently seeing.

Does anybody have an answer here? Any input would be greatly appreciated.

Brian.

[Leon]

Well if you are using Black Walnut, some of it does have black streaks. Will plain water do the same to the same piece of wood? If so, your wood has that coloring. Most finishes do have a temperature range that they ideally should be used at but normally that has more to do with getting an even finish or for proper curing.

[Brian]

It is Peruvian Walnut, and its not a streaking. This is almost an ebonizing. Let me provide some pics of the test piece that worked and the new ones that didn't.

Brian.

[Leon]

Try the water test on a piece of scrap also.

[GerryG]

Have you tried just thinner (mineral spirits) or naphtha? I have a feeling they will do the same. Has the wood been exposed to direct sunlight? If not, is it humid there? I'm thinking trying a bleach wash then rinse, dry and try again.

I assume the prior samples were from the same board, of course.

I'm in similar weather (southern Utah). I don't see the abrupt temp change doing anything to the finish. As for 100 deg, you can expect problems with any finish that normally dries quickly. I do most finishing very early in the day, where it's in the 70's.

GerryG

[Tom Watson]

You've brought a cold substance into contact with a warm substance and created condensation.

Allow the finish to come to the temperature of the material to be finished and try again.

Regards, Tom.

Thomas J.Watson - Cabinetmaker (ret.) tjwatson1ATcomcastDOTnet (real email)

[Brian]

Mineral spirits aren't black.

Brian.

[Brian]

Mineral spirits look clear. No humidity here. Dry heat. I suspect Tom's answer is "the" answer.

Brian.

appreciated.

[Mike Zuchick]

Christ is in our midst.

God Bless you and yours Brian,

I live in the North Western part of North Carolina where the Heat and the Humidity really does a number on Finishes.. I never use Stains and about all I use to seal the wood is Clear Gloss or Satin Polyurethane and still have problems with it drying.. Now I must wait till the Humidity is below 65% before I even consider Sealing anything.

I also wipe everything I do down with Mineral Spirits which gives me a pretty good idea as to what it is going to look like.. I would not suggest water because it can soak into your wood and cause major problems after the Finish has dried, but the Mineral Spirits (Paint Thinner) will evaporate leaving the woods moisture content as it was when you started and will not cause problems with the finish.

So.. Forget the water and use the Mineral Spirits to get an idea of the color the wood is before you apply your seal and wait till the Humidity is between 60% and 65% before you apply your Wood Seal.

God Bless, Michael

[Brian]

Thanks for the input Mike. I don't have a humidity problem where I am now... Just a dry heat. I think another poster may have found the problem, and that is since I store the finishes indoors (cool) and I apply them to a work piece in the garage (hot) I'm getting condensation and muddying everything up. I've got a test piece cooling down indoors, and I'll do a quick application of Danish oil before going to sleep tonight.

Brian.

problem....

appreciated.

[GerryG]

[Leon]

I think I would find a better varnish unless you may be exagerating about having to wait for below 65% humidity. I live in Houston TX where the humidity is rarely below 80% and I don't have those problems. Granted dry time tends to be a bit longer but it certainly does not prohibit applying a varnish of any kind.

Water does not have much effect on the finish when used on scraps and does not have much effect if you are using a water based varnish.

[Wes Stewart]

|Please follow up on this one. I can't see a maybe 20deg difference doing that, |not with low humidity. On that note, has anybody ever checked the temp of the |finish coming out of a spray gun?

If it's a HVLP during the summer in Tucson, it's not cool [g]. I've pretty much settled on shellac and Enduro WB coatings and these dry

*really* fast when I spray outside (my normal routine). I have at times put the spray gun in the fridge for a bit before spraying and haven't seen any problems (so far).

Of course where I live, dust is a major problem, so fast drying has its advantages. I can't imagine using a finish that takes hours to dry.

[David]

Wes, I also use Enduro products. I just got my first can of "Flat". To date I've only used Semi-Gloss and Satin. Have you gotten good clarity by spraying ONLY Satin or Flat? I typically apply a gloss or semi-gloss product to a project, and then apply the final sheen as the last coat. CompliantSpray systems folks swear that it isn't necessary to apply gloss coats for clarity under Satin or Flat.

The humidity in my shop is usually in the 50-60% range and when I spray it's usually in the 70's or 80's. I LOVE the quick drying too! I've had no appreciable problem with dust on any projects so far and I make only a quick attempt to reduce dust in the shop before spraying. I even leave the doors open during and after spraying.

David

Wes Stewart wrote:

[Tom Watson]

I took my clue from his description of the environment as having ambient air temperatures of up to one hundred and even more in his garage, where the wood is stored.

Let's say that the air in the garage is 110F.

The relative humidity would only have to be a bit more than 35% for the 78F material to describe the dew point.

doesn't even take into consideration the microclimate conditions at the surface of the wood due to the moisture that is contributed by the wood itself.

you say, it is interesting.

Regards, Tom.

Thomas J.Watson - Cabinetmaker (ret.) tjwatson1ATcomcastDOTnet (real email)

[Wes Stewart]

|Wes, I also use Enduro products. I just got my first can of |"Flat". To date I've only used Semi-Gloss and Satin. Have |you gotten good clarity by spraying ONLY Satin or Flat? I |typically apply a gloss or semi-gloss product to a project, |and then apply the final sheen as the last coat. |CompliantSpray systems folks swear that it isn't necessary |to apply gloss coats for clarity under Satin or Flat.

David,

I'll confess that I'm fairly new to using their products and to date have stuck with semi-gloss only. I have used multiple coats and to my (maybe uncritical) eye anyway, the clarity has been good. I haven't built anything that required a high gloss finish, so the semi suits my needs. I've been using one or two coats of their sanding sealer and then multiple coats of semi, sanding or using a gray pad between all but the last coat.

I'm confessing too some naiveté about alcohol resistance. I thought that there would be some. Wrong. I used some Gorilla glue in the carcass of a bath vanity I'm building. I wiped up some squeeze out with alcohol and there went my finish. Fortunately it was inside the area where a bank of drawers is going so it won't show.

I'm planning to shoot a final coat with their crosslink additive to improve this characteristic (I'm not looking forward to this for reasons stated below).

| |The humidity in my shop is usually in the 50-60% range and |when I spray it's usually in the 70's or 80's. I LOVE the |quick drying too! I've had no appreciable problem with dust |on any projects so far and I make only a quick attempt to |reduce dust in the shop before spraying. I even leave the |doors open during and after spraying.

I've decided to not spray indoors, primarily for health reasons. It would have been my sister's 54th birthday today, had she not died a horrible death from lung cancer 21 years ago. I partly attribute this to her involvement with furniture refinishing and too cavalier use of the associated chemicals without appropriate precautions. I'm trying to not make the same mistakes.

Lois at Compliant Systems has urged extreme caution with the crosslinked product and I intend to pay attention.

Fortunately, the weather here most of the year is such that I can get away with this. Since I'm not making my living with this stuff, if I can't finish outside, I can do something else.

Wes

[GerryG]

[Mike Zuchick]

Christ is in our midst.

The more moisture the has wood absorbed the more likely the Seal you use will fail.. It may not fail ASAP on a piece of scrap wood, but it will fail.

Failure is caused when the water that is placed on the wood eventually finds an exit. This will cause the surface of the wood where the water was applied to shrink whick causes tiny fractures in the Finished Surface and will lead to a costly re-finishing job..

I am sure you've seen these fractures on a finished surface.. The same will happen if you use wood with high moisture content. But eventually the finish will chip or floof off the surface of the wood turning your finish into dust. This is why I suggest that if you wish to see how the wood will appear before you add the Finish Sealer, use Mineral Spirits.

I've tried the water base Polyurethane once and was not impressed and went back to the Oil Base Finishs.. They last much longer.

God Bless, Michael

[David]

Wes,

I'm still wondering what's in the Crosslinker. I have used it and Lois had told me that it isn't as hazardous as some other catalysts. Did you she give you any idea what's in the Crosslinker? I've tried to find out more about it and have come up empty-handed. I DO wear a respirator when mixing in the Crosslinker or when ever I spray any Enduro product. I hope this stuff isn't gonna lead to some dreadful medical problem! :)

I found that leaving a damp glass on top of Enduro coatings for many hours will compromise the finish. I haven't made any tests on Crosslinked finishes yet.

I generally use one coat of sealer, followed by 3 lightly sanded topcoats. The last project ended up looking too "plastic" so I cut the finish back with gray, maroon and white pads. That gave a nice soft luster and got rid of the dreaded plastic look. I guess I applied too-heavy coats.

What are you spraying with? Forgive me if you've already mentioned that recently; my memory is the pits!

I use an Accuspray #10 w/ .043 tip and #9 cap for the Enduro. Just got me a #5, #6, .028 and .036 for finer control of spraying dye stains and other products. The #5 cap and .028 works GREAT for WB dye stains.

David

Wes Stewart wrote:

[GerryG]