Replies

1. 
   SgianDubh | Jun 18, 2004 02:11am | #1

   strider, you do need to lay out all the facts and information as you know it to get a half decent guess at the problem.

   Fisheye is most commonly caused by contaminants on the surface of the wood or surface being polished. Silicone-- did I get the right spelling?-- and grease spots, etc., are renowned for causing fisheye. The polish crawls away from the problem, like a drop of soap liquid dropped in the middle of an oil film on water causes the oil to migrate to the sides of the container away from the soap drop.   Slainte.

   RJFurniture

1. 
   _strider | Jun 18, 2004 05:24am | #2

   o.k.  sorry i was in class when i wrote the last post.  here is the problem.  and it's fairly complicated. 

   O.k. i have a whole job (large entertainment center) stained in campbells woodsongII stain, country pine if that matters.  end grain shellac'd to maintain even color.  just on the end grain.  no wash coats or glue sizing.  after the project was stained it was coated with polystar.  first coat went on as expected layed out nice.  avg temp was 86 humidity 68.  second coat went on at similar temps and conditions.  things happened at the shop and we were unable to put a final coat on after that until this week.  now the temp is 85-90 with 73-77% humidity.  and now it's fisheye all over.  and it's crawling from knots and stuff badly. 

   the first coat was put on with a graco turbine gun.  but it was taking so long we switched over an old pot (picked up cheap at pawn shop) that had been used for contact adhesive.  it was cleaned extensively.  and the 2nd coat was put on using it with no problems. 

   I really just want to know if the humidity would cause the problems we are seeing.  i really don't trust the m.l. campbell customer service reps.  it's just too easy to write a problem off like this to humidity.  much easier than trying to walk through the possible solutions. 

   well anyways my planned course of action is to shoot some of the same material tomorrow out of a brand new cup gun and see if the problem still exists.  that should let me know if it's contamination from the gun or the material.  or if i have some type of surface contamination.  if no problem from the cup gun that means that the surface is fine and the material is good.  then i would know that it is a problem with the pot/gun/air lines. 

   well anyways TIA all and i appreciate the help

   lee

1. 
   Kevin | Jun 18, 2004 08:34am | #3

   Lee,

   I have limited experience with waterborne lacquer. But, the rep's explanation to you makes no sense to me. I think you are right to suspect the pot, gun or particularly the airlines. Check the moisture trap and make sure it's not letting anything by. From your description, I would suspect either the airlines introducing a contaminent or else something airborne that settled on the piece during the week before the last coat.

   Relative humidity can play a big role in blushing or dry times. But, fisheye? I don't buy that at all. How is water supposed to cause such a surface tension reaction in a water-based product? It makes no sense.

   The Independent Voter.com

   "Rather fail with honor than succeed by fraud" - Sophocles.

1. 
   _strider | Jun 20, 2004 03:12am | #4

   well not sure if anyone really cares but i found somewhat of a reason and a solution. 

   one of the regulators coming off the main airline had packing grease in it that somehow was getting into the lines.  apparently not enough of a situation to affect the lacquer based stuff we were spraying but enough to cause serious problems with teh water borne.  and it was ultrastar not polystar sorry. 

   here's what we did.  we sanded down the surface with 320 which is what i use regularly after the 2nd coat.  then wiped it down with naptha.  occasional fisheyes still show up where i missed a spot or the rag wasn't clean enough or something.  but not enough to be a real problem.  i really don't understand why it didn't fisheye up when the stuff was laying down with the second coat.  but who knows. 

   don't ya'll just love finishing 

   thanks for all your help and if you really want help never call the m.l. campbell customer service reps.  HUMIDITY!  I can't believe she even tried to tell me that.  That's why i had to post this question on here.  I could see drying problems or something but not fisheye. 

1. 
   SgianDubh | Jun 20, 2004 12:32pm | #5

   It seems you've found the main problem strider, and I was interested to read that you appear to have found the solution. Yes finishing can be quite frustrating, ha, ha. I didn't buy the humidity causing the fisheye problem, but I almost never use water based polish products anyway, so couldn't be sure.

   I'm surprised at your reported poor technical support though. I used ML Campbell products for many years when I lived in the US and always found them to be very helpful and knowledgeable about their products. Slainte.RJFurniture

2. 
   _strider | Jun 22, 2004 04:28am | #6

   well i really like m.l. campbells products but so far on several occasions i have been severely disappointed by their customer service reps.  maybe i have just been talking to the wrong people there.  usually when you are calling them nothing is going right in your life anyways so maybe i'll just chalk some of it up to the negativity of the whole experience at the time. 

   But still, to try to blame fisheye on humidity, i just thought that was ludicrous.  I figured i'd get on here and see if anyone else had had a similar experience with ultrastar in high humidity.  well anyways i've been shooting it for the past couple days in 74% humidity or higher and have had no fisheye.  HRMMMMM!  I'm just glad trap coating it worked and it's all laying down satisfactorily now.  well anyways thanks all for the help

   later

3. 
   SgianDubh | Jun 22, 2004 06:41am | #7

   I got used to their products, learned their foibles and funnyosities (sic) and the tricks needed to get a good result, and got to like them.

   If you've never used their pre-cat lacquer be aware that their exhortation to keep the film thickness down to a dry 5 mils (I think that's right) is critical. Their particular pre-cat is liable to suffer cracking mostly across the grain or 'chinese writing' if too thick.

   In practical terms this meant spraying just two coats-- definitely no more than three at about a wet 15 mils thick-- I think I've got that wet film thickness correct from memory.

   You may already know this, in which case I apologise.

   Meanwhile, having moved back to the UK where ML Campbell products aren't available that I know of, I'm trying to get used to the foibles of applying spray finish products from Fiddes a Welsh company, and getting used to using a different spray gun-- one with a suction cup. I haven't used a cup gun for years and had got used to a pressure pot system where your spraying actions are different because you don't often have to adjust the aircap for fan orientation amongst other tricks, ha, ha.

   All polishes and spray guns are not the same. Slainte.RJFurniture