How Long To Wait?

[lift mechanic]

I just put the last coat of Arm-R-Seal on the top of my dinning table. Table is QSWO 1 1/2" x 48" x 72" quite heavy about 200 pounds. I need to flip it over to dye, stain and seal the bottom side.

How long should I wait to flip it over so the top side does not get damaged. I have several shipping blankets to set on the work bench to protect it. The label on the Arm-R-Seal says 30 days to full cure. Surely I don't have to wait that long. I am thinking maybe 5 - 7 days?

[jteneyck]

I just put the last coat of Arm-R-Seal on the top of my dinning table. Table is QSWO 1 1/2" x 48" x 72" quite heavy about 200 pounds. I need to flip it over to dye, stain and seal the bottom side.

How long should I wait to flip it over so the top side does not get damaged. I have several shipping blankets to set on the work bench to protect it. The label on the Arm-R-Seal says 30 days to full cure. Surely I don't have to wait that long. I am thinking maybe 5 - 7 days?

It depends somewhat on the drying conditions and how thick you applied the coats, but I think 5 - 7 days will be plenty.  I typically flip things over after about 3 days and have never had a problem.  

Table tops get heavy in a hurry don't they?  I did an English Walnut table top about 1-1/4" x 42 x 95" and it weighed 120 lbs.  200 pounds is a big step up in the struggle to move it.  Get help.

John

[Rob Young]

3 to 5 days should be fine. Longer is better.

For what it is worth, I do the underside of table tops first. You get a practice surface to use in fine tuning the application and you can flip over relatively quickly and support on a nail board without much worry since it is the less visible side. I generally don't rest parts directly on the moving blanket that covers my bench during finishing.

[jteneyck]

3 to 5 days should be fine. Longer is better.

For what it is worth, I do the underside of table tops first. You get a practice surface to use in fine tuning the application and you can flip over relatively quickly and support on a nail board without much worry since it is the less visible side. I generally don't rest parts directly on the moving blanket that covers my bench during finishing.

That's a good strategy unless you are using dye or stain that might run down over the edge of the table top.  If that happens it will leave a stain no matter what you do short of deep sanding.  So I either finish the top first or tape off the sides and ends of the top if I want to do the bottom first.  

Another lesson learned the hard way.  

John

[lift mechanic]

I finished the top first because of the posibility of getting the aniline dye run on the top. On the large surface I used a 4" foam roller to spread the Arm-R-Seal over the surface, lots of bubbles. Most of the bubbles had popped before I dragged the surface with a applicator sponge/rag. I dragged the applicator very lightly over the surface which popped the rest of the bubbles. I am very happy with the out come. Now I just have to get the table top up stairs. I have done this before. I use a 24' long aluminum pick board. Remove a section of rail from the 12' high deck. place a couple of shipping blankets on it and place the table top on the pick board and slide it up to the deck, pulling it up with a rope. I use a couple of 2x4's clamped to the table top for guides so it won't slide off the side of the pick board.

[Rob Young]

That's a good strategy unless you are using dye or stain that might run down over the edge of the table top.  If that happens it will leave a stain no matter what you do short of deep sanding.  So I either finish the top first or tape off the sides and ends of the top if I want to do the bottom first.  

Another lesson learned the hard way.  

John

I try very hard not to pool dye near and edge. So far, so good.

Last two I dyed were done on both sides in the same session. Using carpet nail strips as my standoffs I could work fast and with light pressure. No issues with denting in oak or cherry. 

Hand applied with sponge these times, not sprayed. And working indoors. I've sprayed dye and there I do mask off edges.

Order was bottom, wipe excess, flip, top, wipe excess, edges, wipe excess. Then flip one more time so bottom resting on nail strips. 

Small enough tops I could flip without it becoming chore. If I was doing something that weighed 200# I would only do one side per half day to allow things to dry. Last batch of interior door I did were large but reasonably light at 40-60# or so.  Not dyed but still flipped multiple times for spraying. Started to think about a jig to hold and flip.

I have also gotten into the habit of making sure all edges are broken on tops to minimize chances of surface tension pulling dye around.

Has worked well for me. No problems so far. Work fast and with a purpose, even more so than glue ups.

Dye is a pain to remove once it has penetrated, that is for sure!

[Cooler]

I have read that a "full cure" for most finishes is 200 hours.  I've seen that number several times from several sources.  I doubt it is completely accurate.  I would guess the finish will achieve 90% of its hardness in the first 7 days (200 hours).  But work I've done that is older and has oil-based poly is noticeably harder than the week-old stuff.  I think 200 hours is safe.  Use fabric or paper over a smooth surface to prevent adhesion. 

I've heard that Benjamin Moore's Advance takes 30 days to cure for light colors and upwards of 3 months for dark colors.  It dries overnight.

I think a single coat of finish might cure in 72 hours, but for horizontal surfaces (like countertops and tabletops) I typically put down 3 or 4 coats.  That will take appreciably longer to cure.  This is especially so if you follow the "recoat in 4 hours and no sanding" recommendation.  If you allow overnight to dry before recoating then each layer of finish has time to cure.  If you bury the first layer under subsequent layers before it can cure it will take much longer to reach something that you can reasonably call a "full cure".

For me, I have two tests for the hardness of a finish.

The first one (marginal test) is the "thumb nail" test.  If I can't scratch or depress the finish with my thumbnail it has passed my "thumbnail test".

The "Penny test" means that when i rub the edge of a penny over the surface it will not be marred.  That is pretty decent hardness for a tabletop and oil-based poly will pass that test after a month with no problems.  It will not pass that test after a week however.  (I do press down as hard as I can to test this.)

It does not matter how you test, as long as your tests are repeatable.  A "pencil test" is standard for the paint industry.  It utilizes pencils that come in various hardnesses to do the same.

This is how it is done:  https://www.youtube.com/watch?v=j5Qd00uJDMQ

[measurecutcurse]

3 to 5 days should be fine. Longer is better.

For what it is worth, I do the underside of table tops first. You get a practice surface to use in fine tuning the application and you can flip over relatively quickly and support on a nail board without much worry since it is the less visible side. I generally don't rest parts directly on the moving blanket that covers my bench during finishing.

I take this approach as well. Also agree 3-5 days is plenty for Arm-r-Seal

[lift mechanic]

After 5 days the finish could not be marked using the finger nail test. A friend stopped by and helped me flip it over. My pick board should be out of the snow in a week or so, perfect timing.

[rwe2156]

Spraying the dye is a good way to go on large tops.

+1 on finishing the underside first, plus you get a preview of the stain.