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  #1  
Old 09-11-2012, 02:21 PM
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Stevesdal Stevesdal is offline
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Question filling and sealing

I'm in dire need of hints and ideas on "how to seal and fill the seams and dimples" in rocket nosecones. When I was building smaller - less expensive kits like Estes, there wasn't an issue with having to fill seams on the nosecones. All I had to be worried about was scraping the "flash" off and sand it smooth.

Now I've moved up to larger kits like mid to high power "Madcow Rockets" and I'm finding the seams and divots in the nosecones are unbearable and impossible to fill. The plastic used allows nothing to stick, even when the nosecone is sanded to give it a grip.

So far I've tried sanding the cone down to rough it up - priming the cone - and cleaning the cone off and starting from scratch when the first two tries didn't work..... Each cone has a little line down each side that's kind of like a little valley. The first filler I tried was Elmers wood filler because of its ease. All it did was flake out of the seam. Next I tried "Fixit" epoxy filler. That didn't work either. It flaked off the cone, (and I did mix it 50/50!).

The tip of the cone has little dimples where the cone isn't smooth. I have no clue what to fill all those with!!!

HOW AM I SUPPOSED TO BUILD MODELS I CAN NOT ONLY PUT ON DISPLAY, BUT FLY WHEN IT ISN'T PERFECT??? Can someone please tell me of a filler or technique to fill the seams and imperfections on the nosecone? Is there a filler someone can recommend?

Thank you.
Steve
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  #2  
Old 09-11-2012, 02:33 PM
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ghrocketman ghrocketman is offline
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Try auto body "spot/glazing putty" made by several companies including DuPont and Bondo.
Squadron White or Green putty at any hobby shop works too.

Before doing either, wash the cone with hot water and dish detergent.
After that, wipe the cone with Lacquer thinner to remove any mold release agents not washed off with the dish soap.
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Old 09-11-2012, 02:43 PM
jetlag jetlag is offline
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Steve,

I use Squadron putty (green) that you can get from your local hobby shop. It can be thinned with acetone if necessary and should stick to your NC. Wetsand with #400 sandpaper after it dries. It should look smooth.

Another type of putty filler that works well is made by Bondo and is called 'Glazing and Spot Putty.' It is reddish in color; I get mine from Pep Boys automotive parts store.

One more kind of putty is made by Evercoat and is called 'Metal Glaze.' The smallest container it is available in (or at least I've found) is a 30 oz plastic bottle; you must use a drop or 2 of activator squeezed out of a tube and mix it up. This stuff is designed for cars, but will work nicely on large rocket jobs you may encounter. It much more costly, though, than the first 2 choices. Once you activate it, you have around 5 minutes to get it where you want before it hardens. I get mine from the Glidden Automotive Paint Store here in Columbia.

As for the right kind of paint, I have used with reasonable success the Krylon 'Fusion' spray paints that are made just for plastic. It seems to adhere well most of the time when
lacquer and regular enamels just will not.


I'm sure others will chime in with what works for them; we have some great builders on the Forum!

Allen

Whoops, I see GH said it also! I type too slowly! Agree with the washing and wiping down he suggested wholeheartedly.

Let me add that nothing you build will be perfect. It will, however, be good enough for you, and that's really all that counts!
The target is always 'museum quality' work or better. I like the wood to look as smooth as plastic, no spirals, and the dents/imperfections addressed as well as I can or am willing to do.

Just have fun doing it! (I think that applies to lots of things )
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Old 09-11-2012, 09:32 PM
chrism chrism is offline
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Putty is a good choice. For smaller dents and divots, you can use gap filling super glue as well.
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Old 09-11-2012, 11:53 PM
johnnwwa johnnwwa is offline
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What everybody else said , this is what I have used for the past seven years. I have filled Madcow NC seams and all my LPR kits to boot (after I have sanded and washed the NC ) I use Tamiya Putty Basic Gray. You may loose some that didn't stick but I usually go over the seams twice anyway. To apply I use a free AARP type credit card( Plastic type) paper ones will not cut it.

http://www.ebay.com/itm/Tamiya-Putt...=item2a218eb7da
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  #6  
Old 09-12-2012, 09:13 AM
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Chas Russell Chas Russell is offline
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I had to make the slog to the local hobby shop (Roy's Hobbies in Hurst, TX) to get Tamiya filler as they only had Squadron green putty. Needed to fix a model for our team's entry at NARAM. Two weeks ago I found the Tamiya white putty at Hobby Lobby. Good stuff, especially if the final color would not hide the green putty well.

Chas
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