Monokote help required

[Keith Black]

I'm not sure if this has anything to do with your problem, but I'll pass it along just as something to be aware of . 

When I Monokoted my plane last season it was the first Monokote job I'd done for almost 20 years (I took a LONG break from RC). I absolutely could NOT get the MK to stick well and was becoming so frustrated that I was seriously considering painting. Then I checked the iron (the 22 year old iron) with a thermometer and found the heat was way below where it should have been, even though the setting on the dial was fine.

I immediately bought a new iron and kept my thermometer close at hand to make sure I knew how hot the iron was. After this it worked great and even survived the summer heat and winter cold quite well.

As to the bubbles, I think others are probably correct that the bubbles are due to the smooth wood. Obviously you don't want the MK melting, but for it to bubble on a smooth non-porous surface is normal. In fact, given that it wasn't bubbling before may indicate that your temp was too low initially.

After re-preparing the surface with sandpaper or a woodpecker you may still have cases where bubbles appear. When I have a bubble that just WON'T escape through the wood, or on MK overlapped on MK, I simply take a small needle, heat the MK creating the bubble, then poke a few tiny holes in the MK on the bubble then hit it with the iron again working the air out through the bubbles. This will let the air escape through the MK and the heat will normally re-seal the hole and the holes will be virtually undetectable. I don't know if this is a common practice, a good idea or bad idea, but it works for me. This trick was shown to me many years ago when I first started using MK.

Keith

  ----- Original Message ----- 
  From: Dean Pappas 
  To: discussion at nsrca.org 
  Sent: Wednesday, March 17, 2004 11:00 AM
  Subject: RE: Monokote help required


  Hi Pete,
  I don't know exactly what your problem is, but your surface preparation may be an issue. The very finest monokote work I have ever seen is done by an ex-Pattern type from Long Island by the name of Stuart Chale. He claimed to have been taught to sand down to #600 sandpaper, and to even burnish the wood with the back side of the sandpaper in high visibility areas. Shiny is good. He uses a tack cloth, as well.

  The mentholated spirits may be an issue. You might try to remove cleaning with methanol. I suspect there is a residue causing your bubbling problem.
  Dean P.
    -----Original Message-----
    From: Peter Pennisi [mailto:pentagon.systems at bigpond.com]
    Sent: Wednesday, March 17, 2004 10:51 AM
    To: discussion at nsrca.org
    Subject: Monokote help required


    Hi All,



    I know this subject has been discussed many times.



    I am currently having some big issues using Monokote - primarily white. Question is can this material go off. I cannot seem to get it to stick properly. If I try to use more heat it will start to bubble. Less heat does nothing. 



    My preparation (regarded by my flying buddies is excellent) the wing is one piece and was wiped down with mentholated spirits to get any loose grain to lift.  I have final sanded the wing with 1200, Timber is shinny. 

    An air compressor with water reservoir was used to blow clean the wing. I then vacuumed the wing. I then used a tack cloth to remove final traces of dust and finally I wiped the wing down with a paper towel with a small amount of acetone to clean the timber prior to covering.



    Mates are using other products more successfully with less fuss. Is it me or is Monokote over-rated. Help needed please.



    Regards,



    Peter


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.f3a.us/pipermail/nsrca-discussion/attachments/20040317/38eb887c/attachment.html