Darryl Keil Last Activity 2025-09-09 11:09 AM
9 replies, 3658 viewings
 
back
Navigate threads:
< Previous Thread :: Next Thread >
 
^ Top
Douglas

Posts: 11

Joined: 2006-12-05
Location: WILKES-BARRE,PA

User Profile 
Subject : cracking in finish
Posted : 2006-12-17 12:58 PM
Post #33502
I veneered flat panel 3/4 MDF doors with raw curly maple,flat maple balancer on back, used plastic resin adhesive in press with heating blanket,had some bleed through,panel sat for days at good shop temp.Sanded and finished with three coats of pre-cat lacquer, natural no stain. Three weeks later cracks in finish running with the grain but not following it. Maybe to thick,to cold,or bad laquer.called manufacture said no problems reported.Sanded back down. Venner looks good no cracks in it,adhesion seems strong, center seam nice and tight. Sprayed two coats in good temp, sat three days small crack in finish running down center seam,but seam is tight.Question is am I getting possible movment or do you think this a finishing problem.Thanks for any input.


 
^ Top
Don Stephan

Posts: 825

Joined: 2003-07-18
Location: Cincinnati, Ohio

User Profile 
Subject : RE: cracking in finish
Posted : 2006-12-17 1:26 PM
Post #33504 - In reply to #33502
My first question would be whether the finish is conforming to tiny but normal irregularities in the veneer. If you've used the finish on other similarly pressed veneer in the past without this experience then this possibility seems less likely.

As an example, it's quite common with the water borne finish I normally use to have a rough surface after the first 2 wet coats on oak, because the finish conforms to the relatively rough surface of oak. I don't have this experience on cherry because it is so very smooth. If the customer wants a smooth finish on oak, sometimes I have to sand back after the first two coats, spray another couple coats and sand back, before the finish is "level". A final coat would then be applied. Some will use "sealer" for building a level surface but I don't spray often enough to justify the extra product inventory.

Commercial plywood often has exhibited the same situation you describe when using my water borne finish. I have also seen it when I have taped together a veneer field and inlay border, even if the veneers are the same thickness. I've never been concerned because I always level sand after the first couple wet coats, even if the surface looks pretty good.


 
^ Top
Douglas

Posts: 11

Joined: 2006-12-05
Location: WILKES-BARRE,PA

User Profile 
Subject : RE: cracking in finish
Posted : 2006-12-18 11:07 AM
Post #33505 - In reply to #33504
Don thanks for your input it's always appreciated. The finish is high gloss pre-cat lacquer rubbed out to a mirror finish ,the closed grain maple was filled with the three coats with no problem,wet sanded and buffed.The crack lets me belive I have movement, but no signs of that,no moisture change or drastic temp change, just don't know


 
^ Top
Don Stephan

Posts: 825

Joined: 2003-07-18
Location: Cincinnati, Ohio

User Profile 
Subject : RE: cracking in finish
Posted : 2006-12-19 9:04 PM
Post #33506 - In reply to #33505
Might consider posting your question on the forums at www.homesteadfinishing.com. Include any prior experience with the finish and how long the finish was allowed to cure before rubbing out. Seems like I read somewhere that finish generally allowed to cure for 2 weeks minimum before rubbing to gloss, but that may have been a recommendation for the water borne acrylic finish I generally use.


 
^ Top
Douglas

Posts: 11

Joined: 2006-12-05
Location: WILKES-BARRE,PA

User Profile 
Subject : RE: cracking in finish
Posted : 2006-12-21 6:04 PM
Post #33513 - In reply to #33506
Don, thanks for that advise ,I will check the site out. I did think maybe I was rubbing out to soon,to rid of all possibilities, so I checked with the manufacturer and I was within a reasonable time frame.Thanks again Doug


 
^ Top
Dan Hill

Posts: 12

Joined: 2005-10-18
Location: S.E Michigan

User Profile 
Subject : RE: cracking in finish
Posted : 2006-12-19 10:25 PM
Post #33507 - In reply to #33502
I purchased some pre-cat lacquer from Sherwin Williams and sprayed two dressers only to find out that the store clerk didn't add the catalyst to the lacquer. The name "Pre-Catalyzed" does not mean the catalyst has been added. I demanded the store manager let me talk to their chemist. He told me to the day, when the finish would crack. A week later the entire finish had cracks just as you described. I spent three days stripping the finish.



 
^ Top
Douglas

Posts: 11

Joined: 2006-12-05
Location: WILKES-BARRE,PA

User Profile 
Subject : RE: cracking in finish
Posted : 2006-12-21 5:59 PM
Post #33512 - In reply to #33507
Dan, thanks a lot for the response, the pre-cat I'm using does have the catalyst already added, so they say.Been using it for a couple years. I think if the catalyst was not added I believe the finish would be some what gummy and take along time to become hard, but could be wrong, you would know I guess. But it does sound like the same problem I had, my finish did get hard but even a week later wasn't rubbing out very well, it took about two weeks or better to crack.thanks again Dan got me thinking now.Doug


 
^ Top
Dan Hill

Posts: 12

Joined: 2005-10-18
Location: S.E Michigan

User Profile 
Subject : RE: cracking in finish
Posted : 2006-12-21 9:16 PM
Post #33514 - In reply to #33512
Doug, My un-catalyzed lacquer dried just as fast as catalyzed. The finish looked great. If you have any of the lacquer left, I would put it on different pieces of wood. Solids, plywood, etc. to see if it cracks. If it does I would bet it's not catalyzed. Hope it’s not the case. Again, good luck.


 
^ Top
Douglas

Posts: 11

Joined: 2006-12-05
Location: WILKES-BARRE,PA

User Profile 
Subject : RE: cracking in finish
Posted : 2006-12-22 6:56 PM
Post #33518 - In reply to #33514
Dan,just wondering what the time was until your lacquer cracked,mine was within about 10 days or so, the 25 cabinets were all assembled and covered up,so I'm not totally sure of the time frame but that seems to be about right.thanks again. Doug


 
^ Top
Dan Hill

Posts: 12

Joined: 2005-10-18
Location: S.E Michigan

User Profile 
Subject : RE: cracking in finish
Posted : 2006-12-22 8:14 PM
Post #33519 - In reply to #33518
Doug, It was about a week or two at the most.
back
Navigate threads:
< Previous Thread :: Next Thread >
Legend      Notification  
Administrator
Forum Moderator
Registered User
Unregistered User
 Toggle e-mail notification


Logo by MAZY
Running MegaBBS ASP Forum Software v1.5.14b public beta