Mite try a trial run. Put say 4 oz of water in the microwave with nothing else and see how hot it gets. Then do test with water and paint sample.
Water will get warmer first run if paint gets warm. The test should be done with same starting temp water so get two 4 oz water samples at same time. See how complicated we can make it, hi. The water in the same container as the paint is on is a notable factor. Do water and paint in separate containers. 73, ron, n9ee/r >From: Burt Lang <[EMAIL PROTECTED]> >Date: 2008/05/04 Sun PM 04:53:41 CDT >To: Repeater-Builder@yahoogroups.com >Subject: Re: [Repeater-Builder] Re: antenna question - Dip It and Scotch Kote > >Think about it. If you expect the water to act as a heatsink, it would >require the cup to transfer heat thru its material. Heat can go both >ways and you will never know if heat generated on the outside is heating >the water or vice versa, the water is passing thru the cup to the >outside. Put a coffee cup of water into your microwave and see how hot >the outside of the cup gets when the water is heated. > >Even if you use a foam cup to isolate the outside from the inside and >are using the water to provide a load on the magnatron (which it doesn't >need), there will be enough moisture in the foam for it to heat up and >probably melt leaving a real mess to cleanup. > >Burt>>> > >MCH wrote: >> You don't care if the cup of water heats up - you are looking to see if >> the painted cup heats up. The water is only there to prevent burning out >> the microwave. >> >> Joe M. >> >> Burt Lang wrote: >>> Fine except for one problem. Water is an excellant absorber of the >>> microwaves used in the microwave ovens (2.45 GHz) So your water will >>> heat up quickly irregardless of the coating. The only substances that >>> are better absorbers of that frequency are animal or vegetable fats >>> because they contain 9 times the molecular bonds (the O-H bond) that >>> actually do the absorbing. >>> >>> Burt VE2BMQ (who used to be a professional chemist) >>> >>> IM Ashford wrote: >>>> Paint a polythene cup with your favourite antenna covering. Let it dry >>>> and put it into the microwave oven along with a cup of water (to act as >>>> a dummy load) >>>> Cook for 1 min on max power. >>>> If it gets even slightly warm its no good for antennas. >>>> >>>> er.. can I please have an award for the first cooking recipe to get past >>>> the moderator on repeater-builder >>>> >>>> Ian >>>> G8PWE >>>> >>>> >>>> ----- Original Message ----- >>>> *From:* skipp025 <mailto:[EMAIL PROTECTED]> >>>> *To:* Repeater-Builder@yahoogroups.com >>>> <mailto:Repeater-Builder@yahoogroups.com> >>>> *Sent:* Sunday, May 04, 2008 2:44 PM >>>> *Subject:* [Repeater-Builder] Re: antenna question - Dip It and >>>> Scotch Kote >>>> >>>> I constructed a 6 meter beam some years back, worked like a bomb >>>> even at 25ft above ground elevation. To ensure my pride and joy >>>> would last a long time I sprayed it with clear Krylon brand spray >>>> paint. >>>> >>>> The antenna was instantly unusable regardless of my efforts to >>>> remove the paint, re-tune or otherwise modify the antenna. I later >>>> learned that type of paint contained materials with a horible >>>> D-Factor. I was never able to use the antenna again, although it >>>> remains in my back yard as a reminder. >>>> >>>> cheers, >>>> s. >>>> >>>> > "Chuck Kelsey" <[EMAIL PROTECTED]> wrote: >>>> > Boy, you took a gamble. I'd have been afraid that this action >>>> > could have either messed up the VSWR or shifted the resonant >>>> > point of the antenna. Then again, maybe it did and either >>>> > you don't know that or it wasn't significant. >>>> > >>>> > Chuck >>>> > WB2EDV >>>> > >>>> > >>>> > ----- Original Message ----- >>>> > From: "skipp025" <[EMAIL PROTECTED]> >>>> > To: <Repeater-Builder@yahoogroups.com >>>> <mailto:Repeater-Builder%40yahoogroups.com>> >>>> > Sent: Sunday, May 04, 2008 12:19 AM >>>> > Subject: [Repeater-Builder] Re: antenna question - Dip It and Scotch >>>> Kote >>>> > >>>> > >>>> > > Hi Robert, >>>> > > >>>> > > You might get lucky... because they might also have advertised >>>> > > the dip-it as an insulator material, which means someone was >>>> > > hopefully looking at the dissipation factor (aka D-Factor) when >>>> > > the compound was engineered. Time will tell... >>>> > > >>>> > > cheers, >>>> > > skipp >>>> > > >>>> > >> "georgiaskywarn" <kd4ydc@> wrote: >>>> > >> Someone else told me that after I had put a whole can of dip >>>> > >> it on the db408 I showed you. I went back and covered every >>>> > >> inch of it with liquid electrical tape. I have had good >>>> > >> results in the GA sun with it. >>>> > >> 73, >>>> > >> Robert >>>> > >> KD4YDC >>>> > >> >>>> > >>>> >>>> >>> ------------------------------------ >>> >>> >>> >>> Yahoo! Groups Links >>> >>> >>> >>> >>> >> >> ------------------------------------ >> >> >> >> Yahoo! Groups Links >> >> >> >> >> > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
