sanding wipe-on poly... need help!

[nroberts]

Hey guys and gals, first time poster here. I'm fairly new to woodworking and can't get enough of it.

I am in the process of refinishing an oak table top (it was painted over and looking pretty sad). After sanding it down to 220 grit, I decided to try the Miniwax wipe-on poly (non gloss finish), since I am inexperienced with finishing and it seemed user friendly.

Searching online helped, but also confused, everyone has a slightly different approach, but what seemed to be a common thread was to sand every few coats (lightly because the stuff is so thin). So I tried sanding with 400 grit, only to find it took the finish off too fast and too much, and left scratches as well. I don't know how people can sand much lighter, must be a learned touch! After abandoning that, I just barely brushed the surface where i felt a few bumps from dust, etc, and left it alone, and proceeded to add layers over the course of a week.

At layer 15 I thought it looked good, so I tried what several people online had recommended for a final sand- automotive sandpaper and water, with a drop of soap as lubricant. Instead of a smooth shinier surface, i now have a duller surface than I previously had, and every line of the open grain is still shiny. Granted, i did not pick the glossy poly, but i thought it would be a bit shinier after the fine sanding.

So, rookie mistake? Am I missing something obvious? Maybe the final sand was meant for high gloss only, I just wanted a smooth surface. By the way, I sanded 2 days after the last coat, which i thought was plenty of time. Any wisdom from the experienced ones here would be greatly appreciated!

[rodger.]

I love minwax wipe on poly, and use it all the time. I typically use the satin formula as well.

Here is a good routine I picked up from FWW when using wipe n poly:

1. Choose nice boards. No finish can make an okay board look fantastic. Take your time and choose your face stock carefully.

2. Sand, and vacuum.

3. Raise the grain by wiping down the project with water. Let dry.

4. Another light sanding and vacuuming

5. Flood wipe only poly on the surface of your project using a disposable foam brush. Keep applying until the wood will not "drink" anymore. Wipe off excess with a clean rag and let dry overnight.

6. Apply a second coat of wipe on poly with a rag, and wet sand (by hand) using 400 grit wet/dry sandpaper. Wipe off excess. Let dry overnight.

7. Apply a very thin coat of wipe on poly with a rag in the direction of the grain. Do not wipe off, let dry for about 2 hours. High humidity could extend this time

8. Repeat step 7 a few times. I usually do 4 or 5 of these thin coats.

9. Let cure for 4 days or so.

10. Apply paste wax with 0000 steel wool and let dry for a few mins (hazes over). Wipe off with more clean rags.

The steel wool helps get rid of any dust nibs that get in your finish.

I have used this approach many times, and it works quite well.

Make sure your rags are laid flat to dry before disposal.

[wtnhighlander]

Good advice from Pug. Another thing you might consider for open pored woog like oak is to fill the pores to give yor top coat a smoother look. There are commercial grain fillers available, but a simple method that leaves the 'depth' of the grain visible is to apply clear shellac to the surface, let it dry, then sand or scrape until the surface between pores is exposed. Repeat until the pores are all filled level with the surface. A good raking light helps to see this. Then apply the desired top coat.

In any event, just remember that the key to a great finish is to have good stock, as Pug said, and to pay your dues in surface prep.

Welcome to the forum, by the way!

[Tkf530]

When scuff sanding, your goal is not to remove the finish but to provide adhesion for the next coat or even sand out imperfects left in your finish. However is you are scuff sanding with 400 (super fine) and taking a pass (exaggeration) and it removes the finish. You either have no finish on or your 400 sandpaper isn't really what you think it is. Scuff sanding should only take a few minutes if not seconds and is my favorite type of sanding. 

 

And sanding will dull your finish. Not increase the sheen. 

[Rapid Roger]

One thing that I do on the last few coats of poly is to "sand" using a piece of brown paper sack. I heard that a paper grocery bag is about the same grit as 4000 grit wet and dry auto body paper.

I guess that it might dull the finish a bit but, with a coat of Minwax rubbed over the surface after a day or two of drying it looks good to me.

 

Rog

[Tkf530]

One thing that I do on the last few coats of poly is to "sand" using a piece of brown paper sack. I heard that a paper grocery bag is about the same grit as 4000 grit wet and dry auto body paper.

I guess that it might dull the finish a bit but, with a coat of Minwax rubbed over the surface after a day or two of drying it looks good to me.

 

Rog

Yup. But I personally used white paper. My grade 9 woodworking teacher taught me this and I remember it to this day. You can also use money.

[nroberts]

Hey everyone, thanks for the quick replies! I guess there's not much in the way of wood prep I can do anymore, short of starting over completely. I understand that sanding typically dulls a surface, it just seemed like what i read was a polishing technique. I'm thinking my best bet is to add a few more layers and leave it be. The table will be a high-use surface, so is there any point to adding wax? Will it last? Thanks for the warm welcome!

[Tpt life]

Nroberts, you had a valid plan. I think the directions you found were incomplete. To polish nibs off rather than scuff, you usually rely on a much higher grit than 400. Even 1500 can still scuff in some soft finishes. You are essentially looking for a burnishing effect or a frictional heat build up if you are polishing for gloss. You have some well respected methods being offered and I think an additional coat or two with a paper follow up will save you from needing to start over.

[rodger.]

Hey everyone, thanks for the quick replies! I guess there's not much in the way of wood prep I can do anymore, short of starting over completely. I understand that sanding typically dulls a surface, it just seemed like what i read was a polishing technique. I'm thinking my best bet is to add a few more layers and leave it be. The table will be a high-use surface, so is there any point to adding wax? Will it last? Thanks for the warm welcome!

Wax is always a good idea in my opinion. Some people skip the wax on high use surfaces, like dining tables, because they get washed so often. I always wax, and if it wears off fast, no biggie!

Fine wood working has a great website for new people in the craft. Goggle "getting started in wood working", and check out their stuff. It's quite good!

[Rapid Roger]

Yup. But I personally used white paper. My grade 9 woodworking teacher taught me this and I remember it to this day. You can also use money.

 

 I got a quarter, will that work?   

 

Rog

[nroberts]

Its great to get input- some forums out there are like a ghost town, thank you again for your replies. I'm feeling a little better about this project turning out well.

When you all mention wax, is it anything in particular? Something specific like from Woodcraft, or even a big box store would carry?

[rodger.]

I use minwax paste wax. You can get it at any big box store.

[nroberts]

Looks like my "adventure"    into sanding with the automotive sandpaper left a few tiny cross-grain sratches.... maybe it picked up some debris. Will that be hidden in the next few coats of poly?

[Barron]

One suggestion for the next project. Use gloss poly for all but the last coat or two. Semi-gloss and flat finish start out as gloss and then fines are added to "dull" the finish. With a lot of coats, you may end up with a "muddy" looking finish. Also, you can sand wet ( before the finish drys) and then wipe off the excess. This helps fill pores.