Finishing the finish

[houstonwoodworker]

I’m using Arm R Seal. How long do I need to let it cure/dry until i can finish the finish with mineral oil and mineral spirits? I’ve never done this before, any other tips?? How long after do I wait to wipe of excess oil??

[Chestnut]

I do 2 days. Curing depends on conditions. If you need more time between costs give the cure more time.

I clean the oil of with alcohol right away.

[Isaac]

Curing times are always highly dependent on your local conditions. Marc talked about this in some of his videos. When in arid Arizona, he would get things to cure in hours that might take a day or more in another location. Generally, waiting longer is the safer bet when you are unsure.

I must confess I have not applied mineral oil / spirits over Arm R Seal. What is the intention with that process?

[gee-dub]

You mention mineral oil and mineral spirits.  Will you use an abrasive as well; sandpaper, pumice, rotten stone?  The cure time varies as stated.  If using an abrasive you want the finish cured, cured, cured.  You want the abrasive to be able to cut cleanly.  For this to happen you don't want the finish to still have "give". 

You can pretty well feel when a finish is still flexible enough to not sand well.  Worst case is that the finish will ball up rather than cut when the abrasive is applied.  A fingernail test in an out of view location can be used as a last resort.

Years ago I tried to get a thicker film than I should have.  The resulting finish took several weeks to cure but, the piece was for my own home so I had the luxury of just waiting.  If it were for a client I would have probably stripped it and re-finished as that would have been faster.  My current home brew of wipe on varnish takes about a week to be ready for "finishing the finish" which I do with 1000 - 1500 grit paper with a felt or cork block and mineral spirits as a lubricant.  I prefer adding more mineral spirits as I go to cleaning the mineral oil off when I'm done.  That is a personal choice and either method works.  Some folks write that they use a bit of dish soap; to each their own at that stage of the process.

Edited October 4, 2018 by gee-dub
Clarity

[drzaius]

Personally, I have never got the mineral oil thing for wet sanding. It just leaves an oily mess that has to be cleaned up. Mineral spirits works very well & is easy to just wipe up after. Or even water with just a couple of drops of dish soap also works well.

[Chestnut]

1 hour ago, drzaius said:

Personally, I have never got the mineral oil thing for wet sanding. It just leaves an oily mess that has to be cleaned up. Mineral spirits works very well & is easy to just wipe up after. Or even water with just a couple of drops of dish soap also works well.

It's mineral spirits with a dash of oil like 5 parts to 1. The oil just helps it not flash off as fast. For clean up a rag soaked in alcohol will cut the oil in one or two quick wipes. Alcohol dries up oil quickly and easily.

2 hours ago, Isaac said:

What is the intention with that process?

Leaves a silky smooth finish. If you've never tried it it's worth trying. I use festool platin pads 2000 grit. if you take your time and do the finish right it leaves a feeling that you can't help but touch. Also it's not an application the mineral oil/mineral spirits is a lubricant to sand at the high grits. Water and wood as we all know don't tend to mix very well. You don't want to accidentally raise the grain after you did a lot of work trying to get things silky smooth. Alcohol flashes off to fast.

[Mark J]

Does one have to use high gloss ARS or can you achieve the smooth feel with a semi-gloss or satin sheen?  

[Isaac]

2 hours ago, Chestnut said:

It's mineral spirits with a dash of oil like 5 parts to 1. The oil just helps it not flash off as fast. For clean up a rag soaked in alcohol will cut the oil in one or two quick wipes. Alcohol dries up oil quickly and easily.

Leaves a silky smooth finish. If you've never tried it it's worth trying. I use festool platin pads 2000 grit. if you take your time and do the finish right it leaves a feeling that you can't help but touch. Also it's not an application the mineral oil/mineral spirits is a lubricant to sand at the high grits. Water and wood as we all know don't tend to mix very well. You don't want to accidentally raise the grain after you did a lot of work trying to get things silky smooth. Alcohol flashes off to fast.

I see. I've wet sanded after finishing, but always just used water. Never had an issue with grain raise that late in the game, seems unlikely seems the surface is already sealed and protected, but I might give this a try.

[houstonwoodworker]

Thx to all. I’m in Houston so very humid. After the 3rd coat, I will bring it inside for 2 days and then back out to shop for finishing the finish. I guess I plan to use 5:1 ratio of mineral oil to spirits and will wipe off right after the wet sanding. I plan to use 1200 sandpaper. 

[Chestnut]

30 minutes ago, Isaac said:

I see. I've wet sanded after finishing, but always just used water. Never had an issue with grain raise that late in the game, seems unlikely seems the surface is already sealed and protected, but I might give this a try. 

The surface is sealed in rough terms but if you look at it finely it's not as sealed as we probably think. There are a lot of opinions that wood finished with an oil based product should not have water applied to it ever for cleaning or any other reason.  I know the wiping poly i use is very thin and doesn't offer a lot of protection from water. It doesn't take much spirits and oil so i mix up a cup and it lasts for 3-4 large projects.

The other factor could be dry time. I know the mineral oil spirits mixture takes a long time to dry and gives me a good 30-60 min of time to work the finish. Water in some ares might dry faster requiring more to be applied. There might also be some lubrication benefit to having the oil in there vs just water. When ever I've seen wet sanding i have always seen soapy water used supposedly to increase lubrication.

If you have a method that works stick with it. My knowledge is limited to what I've tried based off the research I've done. if i'm not using WB finished i don't typically grain raise and then i usually try and keep water away from my projects. I could be acting WAY to careful .... <shrug>.

[Isaac]

Just now, Chestnut said:

The surface is sealed in rough terms but if you look at it finely it's not as sealed as we probably think. There are a lot of opinions that wood finished with an oil based product should not have water applied to it ever for cleaning or any other reason.  I know the wiping poly i use is very thin and doesn't offer a lot of protection from water. It doesn't take much spirits and oil so i mix up a cup and it lasts for 3-4 large projects.

The other factor could be dry time. I know the mineral oil spirits mixture takes a long time to dry and gives me a good 30-60 min of time to work the finish. Water in some ares might dry faster requiring more to be applied. There might also be some lubrication benefit to having the oil in there vs just water. When ever I've seen wet sanding i have always seen soapy water used supposedly to increase lubrication.

If you have a method that works stick with it. My knowledge is limited to what I've tried based off the research I've done. if i'm not using WB finished i don't typically grain raise and then i usually try and keep water away from my projects. I could be acting WAY to careful .... <shrug>.

Interesting, first, I do typically grain raise prior to oil based finishing, so that might be part of the difference right there. 

I'd say adopting the no water exposure ever requirement after the piece is finished is just a bit unreasonable. Of course it will ensure you never have water issues, but realistically, people are going to wipe table tops with damp rags and such. On a finished surface, I've never had an issue unless I left water standing for an extended period. 

[Chestnut]

46 minutes ago, Isaac said:

Interesting, first, I do typically grain raise prior to oil based finishing, so that might be part of the difference right there. 

I'd say adopting the no water exposure ever requirement after the piece is finished is just a bit unreasonable. Of course it will ensure you never have water issues, but realistically, people are going to wipe table tops with damp rags and such. On a finished surface, I've never had an issue unless I left water standing for an extended period. 

Huh good conversation! I don't apply water when i apply oil based because there is some part of my brain that thinks if i apply it unevenly i might get some warping or other movement effects. I haven't had the experience personally but i got the advice from an experienced (aka old) woodworker that was pretty adamant about it.

Keeping water away isn't much of an issue after projects are finished. Despite the fact that I love making tables i don't get a chance to make many of them. I have the one i made 5 years ago and 2 coffee tables. The end tables and other items with tops I've made don't see water use. If food or beverages do get set on them and dirt becomes an issues the one time a year they need more than a wipe with a dry microfiber i clean the tops with alcohol. Coffee tables get cleaned more often but generally with alcohol as well. I use rubbing alcohol to clean a lot of things now that i think about it.

When i make the dining table i want to make i think i'm going to take your advice and raise the grain despite using an oil finish. I like that it might help protect against grain raising so i can clean it with water and not worry.

[Minnesota Steve]

This trick worked fairly well for me:

https://www.popularwoodworking.com/techniques/brown-paper-bag-trick/

Basically just take a brown paper grocery sack and use it to rub out the finish.   It's like an ultra-high grit buffing pad.

 

For myself with Arm-r-Seal... I put on 4-5 coats... I let it dry 24 hours between coats, but that was my schedule.   I sanded lightly between coats with a 600 grit, wiped it down with mineral spirits and then applied the next coat.   The brown paper bag I did as an absolute last step and I felt it gave good results.

Much better and easier to do than any other finish I've tried(brush on poly, brush on water based poly, brush on lacquer).    These might work well with a spray gun, but lacking that the wipe on arm-r-seal worked well and it doesn't stink up the house if I use it in the basement.

[Isaac]

28 minutes ago, Chestnut said:

Huh good conversation! I don't apply water when i apply oil based because there is some part of my brain that thinks if i apply it unevenly i might get some warping or other movement effects. I haven't had the experience personally but i got the advice from an experienced (aka old) woodworker that was pretty adamant about it.

Keeping water away isn't much of an issue after projects are finished. Despite the fact that I love making tables i don't get a chance to make many of them. I have the one i made 5 years ago and 2 coffee tables. The end tables and other items with tops I've made don't see water use. If food or beverages do get set on them and dirt becomes an issues the one time a year they need more than a wipe with a dry microfiber i clean the tops with alcohol. Coffee tables get cleaned more often but generally with alcohol as well. I use rubbing alcohol to clean a lot of things now that i think about it.

When i make the dining table i want to make i think i'm going to take your advice and raise the grain despite using an oil finish. I like that it might help protect against grain raising so i can clean it with water and not worry.

I agree. Man, adopting rubbing alcohol for your normal household cleaning, that is pretty hardcore! I mostly have cabinets I've done and they don't really get dirty either, but I have no fear about wiping them down with a wet rag and immediately wiping it off again. My kitchen table, which i didn't make, but is solid Ash, and we routinely that with a damp cloth after eating. No problems with it to date, though I have given it a light refinish to remove minor nicks and pencil/crayon marks, primarily added by my son.  

[drzaius]

1 hour ago, Isaac said:

I'd say adopting the no water exposure ever requirement after the piece is finished is just a bit unreasonable.

Honestly, I've never had any indication that the water has caused an issue. Water is all I used for years (decades). Sometimes the water seems to make the surface a little grabby with the paper. If that happens I'll switch to mineral spirits. I've never had a problem with spirits flashing off too quickly, but then I live in the great white north & for us 30*C is a hot day.

[wdwerker]

With platin pads or sandpaper remember you want even pressure, not fingertip concentrated pressure. With sandpaper I use a cork block to provide even soft pressure. If the particles start to build up on your abrasive clean it off. I use a gray Scotchbrite pad to clean sandpaper. I use compressed air to clean platin pads . You do not need high speeds or high pressure.

[Mark J]

17 hours ago, Minnesota Steve said:

For myself with Arm-r-Seal... I put on 4-5 coats... I let it dry 24 hours between coats, but that was my schedule.   I sanded lightly between coats with a 600 grit, wiped it down with mineral spirits and then applied the next coat.   The brown paper bag I did as an absolute last step and I felt it gave good results.

The brown paper bag idea is very cool.  Seems like it would be easier than sand paper.  If you are dry sanding between coats of ARS why not use the brown paper bag trick instead of 600 grit?

 

Not to stir up controversy, but we've had oak floors in our kitchen for the last 12 years and they have tollerated occaisional water exposure well.  Before that the old kitchen had had maple floors for 100 years.

Surface coatings that cure by cross linking are not impervious to water, but they do slow down the movement of moisture.

[drzaius]

I'm going to be contrary here & say that I just don't get the brown paper thing. It's has nowhere near the abrasive qualities of 600 grit. I've tried it a couple of times & it doesn't seem to do much of anything.

 

[wdwerker]

I've used brown paper in a pinch several times. It's more of a buff than abrasive I think. Took a finish that had been rubbed w a gray pad then a white pad from a shiny satin to a semigloss. 

[Jfitz]

53 minutes ago, drzaius said:

It's has nowhere near the abrasive qualities of 600 grit. I've tried it a couple of times & it doesn't seem to do much of anything

IMO, that's a good thing.  If I wanted 600 grit, I'd use it. +1 to Steve's comment - it's more of a buff for final touchups.

[Pondhockey]

My builder uses the "brown paper bag trick" specifically to smooth raised grain (particularly when finishing wood trim.)

I've tried it and agree it's not as aggressive as sand paper.

[wdwerker]

Heavy bag paper is coarser than the thin roll type brown paper for wrapping.  Decent heavy brown paper bags are fairly scarce these days. 

[houstonwoodworker]

For those of you that said to wipe off with alcohol, are you referring to denatured alcohol?

[Chestnut]

35 minutes ago, houstonwoodworker said:

For those of you that said to wipe off with alcohol, are you referring to denatured alcohol?

Or rubbing alcohol but yes i use denatured because i have a gallon can of it readily avilable.

[AceHoleInOne]

On 10/3/2018 at 8:00 AM, houstonwoodworker said:

I’m using Arm R Seal. How long do I need to let it cure/dry until i can finish the finish with mineral oil and mineral spirits? I’ve never done this before, any other tips?? How long after do I wait to wipe of excess oil??

The longer the better. You should only rub a FULLY cured finish. ARS is about 3o days for fully cured. Do yourself a favor, simply use water with a little dish-soap. The reason the old guys used MS or MO as a lube, was is in-case of rub through (typically machine sanding). Water could swell the grain and cause more issues. However, if you have a decent build and you know what you're doing...water and soap is no issue!

You should only lube rub a FINISH that HAS A GOOD BUILD/MILL THICKNESS.  Remember, rubbing removes finish!

The paper bag thing does nothing for a finish other than to knock down a few minor sharp dust nibs of a final coat.  It's not a substitute or catch all for a bad a finishing schedule and not to be used between coats. Between coats, a finish needs a sand scratch with sand paper for the next coat of finish to hang on to while it levels and smooths.   

-Ace-