ranger461vs Posted February 24, 2014 Report Share Posted February 24, 2014 Hi I'm new to this site and lure making. I have been air brushing some blank crank baits and went to seal them and used moisture cured urethane. The finish looked great except for a series of small fine bubbles running down the back. Does anyone have a solution to this problem our seen it happening their lures also. Quote Link to comment Share on other sites More sharing options...
Reelentless Posted February 25, 2014 Report Share Posted February 25, 2014 Could be your blank wasn't properly sealed to begin with and after heat setting your last coat of paint -air was slowly escaping causing the bubbles. Quote Link to comment Share on other sites More sharing options...
seanmarty93 Posted February 26, 2014 Report Share Posted February 26, 2014 Are you using wooden blanks or plastic? Quote Link to comment Share on other sites More sharing options...
BobP Posted February 26, 2014 Report Share Posted February 26, 2014 MCU tends to form bubbles if it is too thick anywhere on the lure, so I recommend just hanging the lure up after application so excess MCU drips off the tail of the lure. It also behaves badly with many solvent based coatings, so if you used one underneath the MCU, it can cause bubbling or lifting of your paint. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted February 26, 2014 Report Share Posted February 26, 2014 Bob, Does adding a couple of coats of Createx clear gloss provide enough protection so the MCU doesn't get down to the underlying layers that it might otherwise react with? Quote Link to comment Share on other sites More sharing options...
BobP Posted February 27, 2014 Report Share Posted February 27, 2014 Mark, I like the MCU to penetrate the acrylic paint and bond to the undercoating (which in my case is usually epoxy). It forms a very durable monolithic finish - as I found out when stripping lures that had been MCU topcoated. Acrylic paint that is dried with a hair dryer is just that - dried but not actually cured as it would be if heated to above 300 F. I think dried acrylic is porous and will naturally wick solvents and MCU down to the undercoat. I don't know how many coats of Createx clear would be needed to stop that. Dick Nite MCU when fresh will penetrate very quickly. After it ages and begins to thicken, its penetrating power drops off. I haven't seen the same penetration with other brands of MCU (Garco, Famowood) that have higher viscosity. If you can stand the storage limitations (not sure I can!) DN/MCU is a snap to use - apply it quick (dip or brush) and simply hang the lure up to dry and begin to cure. Doing anything else has always caused problems for me, especially rotating the lure after application which almost always causes areas of bubbling. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted February 27, 2014 Report Share Posted February 27, 2014 Thanks Bob. Quote Link to comment Share on other sites More sharing options...
ranger461vs Posted February 27, 2014 Author Report Share Posted February 27, 2014 Wow thanks buys for all the comments. To answer some questions the cranks are plastic, and yes I have been dunking them in miracle glaze mcu. I did heat set them andcoated them.when I coated them I hung them to dry. I did only do one coat do they need a second? Quote Link to comment Share on other sites More sharing options...
BobP Posted February 27, 2014 Report Share Posted February 27, 2014 (edited) MCU is amazingly tough stuff after it cures, I think maybe the toughest topcoat you can get that is also thin and "factory-like". I do a single coat on bass baits and have never had any issues with its performance. In fact, doing multiple coats of MCU can be chancy if you want to avoid bubbles. I can't specifically comment on your particular brand of MCU, but all the brands I've tried are similar in durability. Edited February 27, 2014 by BobP 1 Quote Link to comment Share on other sites More sharing options...