# Poly finishing problems



## JBeck (Feb 18, 2009)

I just completed two Sierra pens in amboyna burl one a click version and one a elegant version.  The problem I'm having is that the finish on both of these burls pitted.  I'm very careful to wipe down with a tack cloth between coats of finish so I'm pretty sure the pitting is not caused by dust.  The finishing method I used is as follows:

1. Sanded MM to 12,000
2. 2 coats of shellac sanding sealer, sanding with 600 grit between coats
3. 3 coats of Minwax fast drying poly, sanding with 1500 grit (lathe stopped) between coats.  4 hrs or more cure time between coats.
4. 3 more coats of Minwax fast drying poly without sanding between coats.  Note all coats of Minwax poly was left to dry for at least 4 hrs prior to putting on the next coat
5.  After the final coat, it was left to cure for 24 hrs, then buffed starting with MM 6,000 - 12,000.  Then buffed with Brasso.

I saw this method posted somewhere on this forum but don't remember where - sorry.

I was told that since it was a burl I was finishing, that the pitting may just have been a natural part of the wood and that I should have put more coats of shellac to level out the wood before applying the poly.  

I would appreciate some of you finishing experts to weigh in on what I may or may not be doing wrong.  And any advise would be greatly appreciated.

John


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## marcruby (Feb 18, 2009)

I think you're sanding too much at the beginning and not enough at the end.

No matter how many coats you put on you have to make sure the coats are level before moving on to the next stage.  If I read you right there was pitting in the final coat.  You should have dropped back to a grit that would let you remove any unevenness and then sanded forward through the grits.  I think you have more enough poly on the pen that you shouldn't have to worry about sanding through to the wood.

Another thing.  Sanding sealer won't always seal away the pits in its own.  Try applying a coat of sealer and then sanding right away, letting the sealer/dust slush fill any pits and cracks.  Then another coat of sealer, sand it out when it's dry and then run up the grits, applying layers of poly as you go.  If you see pits, stop and sand them out before going any further.

Marc


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## Tn-Steve (Feb 18, 2009)

Marc,

     You just saved me from having to post a question on the best way to use sanding sealer.  I've been having pitting problems too, and now I've got something to try.

    As for the OP's question, I'm a rank novice when it comes to finishing, I just now have got a CA technique that seems to work well, but one thing that I learned a long time ago in a different life is that if you have a problem with one of the base layers, any finish on that tends to MAGNIFY not diminish the problem.  A sanding scratch that is unnoticeable on bare wood becomes magnified by all the layers of finish, the same way a pit, despite the fact that it creates an almost microscopic difference in the final smoothness of the finish sticks out like a biker at a débutantes ball.

As painful as it is for me, sometimes I have to just go back and undo what I had done, to get it to where I want it to be.

Hope this helps,

Steve


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## JBeck (Feb 18, 2009)

Marc, 

Let me make sure I understand you.  First I should apply the sealer (shellac), then wet sand immediately.  Do I then let that dry before applying another coat of shellac?  Because if I apply another layer of shellac right after sanding won't I wipe away all the dust I filled the pores/pits with?  

Thanks,
John


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## jttheclockman (Feb 18, 2009)

Are these raised specks or are these craters???  Because I sugest you seal with CA as your base coat to level the blank of all defects. Sand down using a backer on the sandpaper so it is a little stiffer. Then go from there.


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## JohnU (Feb 18, 2009)

I agree with jttheclockman, I seal with ca first and sand smooth.  It seals and levels any dimples or low areas. How many layers of ca depends on the depth of the low areas,  then I apply my finish.


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## marcruby (Feb 18, 2009)

The idea with the first sealer coat is to create a slurry which will fill in cracks, etc.  Then let it dry and sand it even.  Then you can put on a second coat and let that dry.  Or not,  if things look good you can switch to poly right then.  You have to decide what to do based on what's happen as the finish develops.  I generally us CA as the sealer coat - since I usually use CA as a finish, but the approach works whatever treatments you choose.  On bowls I use Velvit Oil as the sealing coat and Waterlox as the finish.  I'm planning on trying that on a pen shortly.

Marc



JBeck said:


> Marc,
> 
> Let me make sure I understand you.  First I should apply the sealer (shellac), then wet sand immediately.  Do I then let that dry before applying another coat of shellac?  Because if I apply another layer of shellac right after sanding won't I wipe away all the dust I filled the pores/pits with?
> 
> ...


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## GouletPens (Feb 18, 2009)

FWIW, you're wasting your time with all these coats. For the first year I was making pens I tried every natural finish under the sun with every kind of sealer and I finally found a great process that made the pen look like glass.....problem is that anyone that touches the pen will destroy that finish in a couple of weeks with the oils in their hands and all your hard work will be for naught. Natural finishes are great for a lot of things but a waste of time on pens. Master a CA finish and spend more time doing actual turning.:biggrin:


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## ldb2000 (Feb 19, 2009)

GouletPens said:


> FWIW, you're wasting your time with all these coats. For the first year I was making pens I tried every natural finish under the sun with every kind of sealer and I finally found a great process that made the pen look like glass.....problem is that anyone that touches the pen will destroy that finish in a couple of weeks with the oils in their hands and all your hard work will be for naught. Natural finishes are great for a lot of things but a waste of time on pens. Master a CA finish and spend more time doing actual turning.:biggrin:


 

Brian , the finish they are talking about isn't a natural finish , it's Polyurethane finish  , about as plastic as CA . This is the same finish that wood floors are finished with . Pens finished with it are as shiny and durable as CA , once cured . 

John , can you post a picture of the pits , it might help if we could see the problem . Are the pits in the finish itself or are they telegraphing through from the wood .


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## marcruby (Feb 19, 2009)

GouletPens said:


> Natural finishes are great for a lot of things but a waste of time on pens. Master a CA finish and spend more time doing actual turning.:biggrin:



Actually, poly can be every bit as durable as CA.  It's what goes on many wood tables and floors and takes more abuse than most pens ever will.  Tung oil based finishes are pretty durable as well.  What makes CA a good finish isn't so much durability as that it's fast.  It takes me at least 6 days to lay a tung out finish on a bowl.  I suspect even longer for a pen.

And CA has a number of drawbacks.  One is that when it does wear it looks terrible, and is irrepairable.  That can be a major issue when you are selling a $600 pen.  And when it's really shiny it looks like plastic.  That's why I intend to experiment - When I tell a guy that the wood in a pen comes from an extinct tree I want him to feel the wood, not squint at the glare.  I use a lot of CA, and I do a pretty good job with it.  I just don't believe it's the ultimate finish.

Marc


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## ldb2000 (Feb 19, 2009)

Marc , I use Teak oil as a finish on some woods that people want to feel the wood , like BOW . I had read on a website about baking in a teak/tung oil finish . what you do in a nutshell is sand the wood to final sanding then treat the wood with teak/tung (it's really the same thing) till it can't take anymore in , then wipe off the excess and bake in a kiln at 125 degrees for 8 hours . Baking forces the oil to dry and harden in the surface of the wood then you just buff to a final gloss . I use this method on certain woods including BOW and so far it seems to work great , leaves a nice natural looking finish that's durable .


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## JBeck (Feb 19, 2009)

Butch, I haven't taken pictures of the pen yet and I haven't figured out how to post pictures as of yet.  I've followed the FAQ explanation of creating a photo album, but I can't find anywhere where in my CP where is say's "create album."  Any help would be appreciated.  

The pits are not raised, they are depressions in the wood which leaves me to believe they may be in the wood itself.

So you can apply poly over a CA base and the poly will adhere OK?  I tried CA only finish (thin CA only) and it turned out great on my experimental piece of wood and my first pen.  So I guess I got over confident and I've had mixed results with CA ever since, so that's why I'm trying the poly method.  The jury's still out.  I'm finding the turning part is easy (or easier) and the finishing part is a lot harder to perfect.

John


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## ldb2000 (Feb 19, 2009)

John , yes I use thin CA as a sealer coat . I apply the CA with a piece of 400 sandpaper creating a CA/wood dust slurry that fills any open grain and imperfections in the wood . Then I follow Les's instructions for applying the Poly , the only thing that I do differently is to let the poly dry in a kiln at 125 degrees for one hour and repeat for 6 coats .
It leaves a really nice finish .


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## GouletPens (Feb 19, 2009)

marcruby said:


> Actually, poly can be every bit as durable as CA. It's what goes on many wood tables and floors and takes more abuse than most pens ever will. Tung oil based finishes are pretty durable as well. What makes CA a good finish isn't so much durability as that it's fast. It takes me at least 6 days to lay a tung out finish on a bowl. I suspect even longer for a pen.
> 
> And CA has a number of drawbacks. One is that when it does wear it looks terrible, and is irrepairable. That can be a major issue when you are selling a $600 pen. And when it's really shiny it looks like plastic. That's why I intend to experiment - When I tell a guy that the wood in a pen comes from an extinct tree I want him to feel the wood, not squint at the glare. I use a lot of CA, and I do a pretty good job with it. I just don't believe it's the ultimate finish.
> 
> Marc


 
My apologies about bashing natural finishes...I read the original post too fast and jumped to conclusions.....that's what I get for typing while tired:tongue:

Can you thin out the poly to a wiping consistency to speed up the drying? Also, how does it wear against hand oils? Pens are a bit unique in that respect, the oils in your hands break down most finishes faster than most other forms of wear. I'm just wondering if a poly finish is really practical for more than just a pen here and there or if its just too time consuming to do regularly.

As with ANY finish, all we're really doing is delaying the inevitable wear and destruction of the wood. The better finishes really just delay this process longer than others.


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## JBeck (Feb 19, 2009)

Thanks for the good info everyone.  Maybe one of these days I'll get this figured out.   

Butch, I assume that I could use an oven set at 125 and do the same thing for an hour.  Is that right?  After that hour, can you sand and recoat right a way?  If so, that would sure speed up the process!

John


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## ldb2000 (Feb 19, 2009)

JBeck said:


> Thanks for the good info everyone. Maybe one of these days I'll get this figured out.
> 
> Butch, I assume that I could use an oven set at 125 and do the same thing for an hour. Is that right? After that hour, can you sand and recoat right a way? If so, that would sure speed up the process!
> 
> John


 
Yes I sand and recoat in an hour and can do several blanks at once . 
I'm not sure about the oven , the poly is combustible , an electric oven would be ok I guess but I don't know .
I use a home made kiln . I use it for drying wood too . It's made of an aluminum foil lined Styrofoam ice chest (the aluminum foil keeps the heater from melting the styrofoam...DAMHIKT) and a fish tank heater and it holds a constant temp of 125 or whatever I set the heater at . It don't look too pretty but it works great and you can make one for about $20 depending where you get the heater . I used spray glue to line the cooler with the foil and put the heater centered in the back (bottom , cooler laying on its side) and a wire shoe rack as a self standing shelf .


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## JBeck (Feb 19, 2009)

That is a great idea.  I may have to build one and give it a try.  Thanks for the info.

John


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## JBeck (Feb 19, 2009)

Just thought of something.  It's probably a stupid question but I'm going to ask it anyway.

If I use CA as my sealing coat and I apply it using 400 grit, then prior to applying the CA it would be useless to sand past 400 grit since the 400 grit would undo any sanding higher than that.  Is my thinking correct?  Then after I apply 1 or 2 coats of CA as a sealer, I would sand from say 600 grit to MM 12000 to smooth out the CA, then proceed with my poly application.  Am I on the right track?  I'm probably making this harder than it needs to be.  :-(

John


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## JBeck (Feb 19, 2009)

Here are a couple of picture of the pen in question.  This is my first time trying to post a picture so I hope this works.


John


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## NewLondon88 (Feb 19, 2009)

GouletPens said:


> Can you thin out the poly to a wiping consistency to speed up the drying?



I've thinned it out with mineral spirits and naptha (and added a tiny bit of
Japan Drier) and it thins out well and dries fast. Not as fast as CA, but fast.


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## pgfitzgerald (Feb 19, 2009)

If the "pits" look kind of like orange peel, I've had that problem on afzelia and amboyna burl finished with minwax poly (I use Les Elm's technique, which can be found in the forum library). I tried a couple of coats of zinsser seal-coat first and it helped a lot.

But... I think Marc hit the nail on the head: too much sanding at the start and not enough sanding at the end. I use 1500MM after the seal-coat just enough to smooth things out and only between the first couple of coats of poly if I think it needs it. Personally, I think 600grit is too coarse.

After two coats of the seal-coat and six coats of the poly, I start sanding at 1500MM to rid the pen of any remaining depressions. But be careful here. If your coats were too thin, you'll go right through all six coats. I also noticed that if there are depressions left after getting to 12000MM, they'll be accentuated when you use the brasso. So when I start, I sand a few seconds, stop the lathe and check my progress, and continue until it has evened out. Then I continue through the remaining MM grits.

On the other hand...

The seal-coat and poly technique also works quite well on porous woods. If you don't want the pores to be filled, don't slurry sand with the sanding sealer and don't use the brasso, which will fill the pores even after the poly has been applied. I just assembled a Gatsby made from Bocote and finished with two coats of seal-coat and two coats of poly. I lightly sanded the seal-coat and didn't sand the poly at all. In fact, I didn't even polish it with MM prior to assembly. It's beautiful, very shiny, no orange peel, and you can see and feel the pores... a very natural looking finish. I think this particular pen may have had a little help from dumb luck though.  :biggrin:

Paul


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## BruceA (Feb 19, 2009)

*Suggestions from a fellow TN. penturner*

John, 
You've got a good start on good taste - amboyna on BlackTi-Platinum Elegant Beauty Sierra.  

With your blank, it looks like it's actually narrower in the center of the blank.  If you don't put a slight bulge in the blank, it's going to look narrowed, even if it's straight across in diameter.  

With a Sierra, the bushings are .474 usually.  Take your blank down to .481, and about .512 in the center, or even 2/3rds up towards the top of the pen. 

If you don't have a digital caliper, get one.  They're about $17. at Harbor Freight and are crucial for accuracy. 

Also pick up the Harbor Freight 5-piece Long Punch set for $6.99.  The largest punch in the set is perfect for disassembly of a Sierra - stick the punch into the blank and give it a rap and the top of the Sierra pops right off.   

The punch is also great for cleaning glue out of the brass tube - apply pressure to one side of the tube and any remaining glue gets sheared out. 

And...finishing wood is The challenge.  Try some acrylics once in a while to increase self-worth.

Bruce in TN. (Fayetteville)


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## JBeck (Feb 20, 2009)

Bruce, 

Thanks for the constructive criticism, I think you might be right about it being slightly narrower in the middle.  I do have calipers that I bought at Harbor Freight, but I've been concentrating on getting the transitions correct and not paying as much attention to the middle.  I've heard about people making the middle of their pens more fat but I haven't really tried that yet.  I will try it on my next pen.  

I have done a couple of acrylics and while I don't like working with acrylic as much as wood, they do finish like a dream.

John


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## ldb2000 (Feb 20, 2009)

John , I have been looking at those pics and the spots I see are in the wood . I think it's just a question of better prep work . The sealer coat , no matter what you use , has to fill all the imperfections in the blank . From what I see the pits are along the grain lines and are probably due to cracks or voids in the wood that just wern't filled all the way in .


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## JBeck (Feb 20, 2009)

Thanks Butch for your evaluation.  Since I've only been turning pens since around Christmas it's nice to have more experienced eyes critique my work.  I will try and work harder on my prep work next time.  The problem is that it is easy to miss things until you start building the finish and problems start to appear that you didn't see before.  The important thing is I'm having fun while learning.

John


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## NewLondon88 (Feb 20, 2009)

JBeck said:


> The problem is that it is easy to miss things until you start building the finish and problems start to appear that you didn't see before.



exactly! :biggrin:


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