Replies

1. 
   Danford_C._Jennings | Jun 20, 2001 05:24am | #1

   *
   Janet,

   FWIW, if a "plumbers brush" is what I think it is, use a better brush with China bristles, Linzer and Purdy are pretty good.

   I would also suggest that after loading your brush don't use the can lip to unload the one side, let it drip and turn it (the brush) up as you take it to the work piece.

   Over working the area can also cause what appears to be air bubbles but are really minute balls of hardened finish. Dust particles can also give the appearance of dried air bubbles. FWIW.

   Dano

1. 
   Gretchen_ | Jun 20, 2001 01:20pm | #2

   *I also just wonder if in the long run using a more flexible varnish like marine spar would be better for your baskets. (It also might be more authentic with the tradition of the baskets--don't know as a fact.) Poly is more rigid and brittle. Of course, do not shake the varnish to mix. Agree with what Dan has said above also.

1. 
   janet_tucker | Jun 20, 2001 03:13pm | #3

   *Thanks Gretchen and Dan,My bases are cherry. It looks to me like the bubbles come up out of the wood into the poly while it is drying. Is there anything I can do to stop this. I read somewhere that heating up the wood before you poly would help with the air bubbles. I pre-coat my bases with a gel poly before I make my baskets to protect them from water while I am weaving. If I switch to varnish is it ok to varnish over gel polyurethane?You are right, Gretchen, varnish is the more traditional finish for Nantuckets, but I have seen people use tung oil and shellac also. What is the difference between varnish, polyurethane and shellac? I really do like the poly finish, just not those air bubbles.Thanks for all the help.....Janet

1. 
   Danford_C._Jennings | Jun 21, 2001 04:38am | #4

   *Janet,Gel urethane? Guess I must be a little behind, I have never heard of it. So I best not try to answer that question.Since you are 100% positive that these air bubbles appear as it is drying after following my previous suggestions, I can't answer that one either since I have never experienced this phenomena.Aside from the obvious differences in the compounds, the main differences between varnish, polyurethane, and shellac would be in hardness and drying time. Poly being the hardest and varnish being the softest. Each manufacturer has different formulations so with the information at hand, I will go no further.Dano

1. 
   Gretchen_ | Jun 21, 2001 04:24pm | #5

   *I would guess it is gel stain with some varnish in it for a one coat finish.While agreeing that from hard to soft is poly, shellac (no water repellency) and varnish it has little to do with a basket finish that will not get surface wear. Flexibility would be more of a concern perhaps. I feel the same way as with wood finishing--a Nantucket basket is a beautiful piece of artistry--why cover it with a coat of plastic (poly).

2. 
   Dave_Arbuckle | Jun 21, 2001 04:40pm | #6

   *I believe Bartley gel varnish is a polyurethane, but I'm not certain (can's at home).Dano, I'm afraid I must disagree regarding relative hardness. Shellac is a lot harder the poly varnish, which is softer even than "traditional" short oil varnish.Polyurethane is added for the purpose of "toughness", which is a lot different than "hardness". Witness a glass window and a lexan window. Glass is harder, almost anything will scratch lexan. But, hit a baseball at each of them, and only one is likely to break.Dave

3. 
   janet_tucker | Jun 21, 2001 05:15pm | #7

   *Hi Dano,Just to clear up the polyurethane gel thing, the brand I use is Mastercraft Polyurethane Gel Wipe-On Clear Coat. I use it to seal my bases before I start my baskets to protect it from water spots. I have read a lot of previous posts and have found others with pimples or bubbles in their polyurethane finishes. I guess it is because there is so much open time drying that it is almost impossible not to have some dust particles land in the polyurethane that can cause pimples. As to the air bubble thing, I did find a previous post that suggested heating up the wood before polying. I might try that and see if that helps. I guess I have also learned that to get a professional looking unblemished finish I would either need to wipe on all of my coats of polyurethane, which would probably mean 8 coats, or rub out the finish when I am done. Seeing how this is a basket and the base on the inside of the basket is not real easy to get to, rubbing out the finish would be very hard to do. So I guess I have at least the answers to my question and now have to make a decision to just let the bubbles or pimples, if the occur, be or try one of the other methods I mentioned above. After all, as I keep telling myself, it is handmade right, it shouldn't be perfect!! Thank you everyone for all of your comments and suggestions!!

4. 
   Gretchen_ | Jun 25, 2001 03:34pm | #8

   *Rather than wiping on your thinned coats you can brush them on using a foam brush and wipe off the excess. Your dilution also doesn't need to be 50/50--it could be heavier on the varnish side but still be a bit faster drying. If these are dust bumps I would think you could control that on something small like a basket by applying the varnish and then putting it in some sort of enclosure to keep dust away.

5. 
   Danford_C._Jennings | Jun 25, 2001 04:06pm | #9

   *Dave, no problem. My experience shows otherwise, could product brand cause the differences? When I think of finish, I think in terms of "hardness" and durability (toughness). Polyurethane, in my experience, is both harder and tougher than traditional varnish. Varnish remains flexible even after it "cures" (it never fully cures).I use all three pretty extensively and find that varnish is the easiest to sand, then shellac, and finally poly. I will say that Minwax Helmsman Spar Urethane has very similar properties to spar varnish.As a very unscientific test, finish a piece of, let's say, Doug Fir with 6 coats of varnish on one area, six coats of poly on another area, and six coats of shellac on still another area. After the piece has sat for about a week, take a ball peen hammer and give the piece a rap on each finish area, you will notice that the poly will spider web around the area of impact, while the varnish and shellac won't.FWIW, as I was trying to figure out what was wrong with Taunton's server I was doing some browsing in their i Fine WoodWorkingsection and found a reference to gel polyurethane, forget who the manufacturer was though as I am not a fan of gel finishes.Dano

6. 
   Dave_Arbuckle | Jun 25, 2001 06:32pm | #10

   *That has to be a brand thing, Dano. I would expect a very different result.Varnishes themselves ("polyurethane" is an additive to varnish) vary greatly according to the resins used, and the amount of oils in them (and undoubtedly a huge number of other factors).For example, the typical spar varnish is a long-oil, probably phenolic resin-based varnish. The goal is to make a flexible finish so the heat/cold cycles and impacts of boating life won't crack it.In contrast, Behlen's Rock Hard is a short-oil phenolic (I think) varnish. It's formulation is primarily to allow a very high gloss to be brought up, it can shine like glass. However, if you use your hammer test on it, it will also break like glass. I would be surprised though, if the shellac wouldn't crack with that test.I too don't care for gels. The oft-cited ease of application eludes me, I find either wiped or brushed varnish to be easier to work with. To each their own, sure is great to have all sorts of product to work with. :-)Dave

7. 
   Danford_C._Jennings | Jun 27, 2001 06:45pm | #11

   *Dave,Good post, your explaination about marine spar varnish is precisely why I use Interlux or Epifanes and always recommend it to others.As the shellac, try it. You don't really think that I would post something here and risk the wrath of whomever, with out having done it myself do you?:)Dano

8. 
   Christopher_Corvi | Jul 20, 2001 07:34pm | #12

   *Question? Arent tiny bubbles a sign of over brushing polys!

9. 
   Danford_C._Jennings | Jul 20, 2001 08:01pm | #13

   *Christopher,I don't think so. The symptons of overworking the area generally are minute balls, a little larger than dust particles, you will also notice the brush "dragging".Air bubbles generally result from improper brush unloading and a can that has been shaken. To much pressure on the brush during application can also cause bubbles.Dano

10. 
    Dave_Arbuckle | Jul 20, 2001 08:30pm | #14

    *You can get bubbles in waterbourne poly by overbrushing. Even easier if you use a foam brush.Like Dano, I don't think you'd get it in oil-based. Seems like you would have to be working at it to entrain bubbles that way.Dave