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Building Tips and technical articles. => Paint and finishing => Topic started by: wwwarbird on March 10, 2015, 08:24:08 PM

Title: You know that point when you think you're ready for paint...?
Post by: wwwarbird on March 10, 2015, 08:24:08 PM: ...and you shoot a nice primer basecoat only to discover a bazillion tiny pinholes in the wing covering? I'm there. HB~>
Title: Re: You know that point when you think you're ready for paint...?
Post by: Tim Wescott on March 10, 2015, 09:54:43 PM: I'm at least a month away from that point on my next world beater, so I can laugh.

Next month, however...
Title: Re: You know that point when you think you're ready for paint...?
Post by: john e. holliday on March 11, 2015, 11:35:47 AM: It is some thing when you think you are ready for paint and spray the primer coat on. Where did all that grain come from. HB~>
Title: Re: You know that point when you think you're ready for paint...?
Post by: bruce finley on March 11, 2015, 05:28:10 PM: Good to know I'm not the only one.............. H^^ H^^
Title: Re: You know that point when you think you're ready for paint...?
Post by: Damian Paten on March 12, 2015, 04:06:50 AM: No good wwwarbird. I wish you luck. Finishing takes longer than the build.
I am at the "ready to prime" stage now with my Nobler.
Title: Re: You know that point when you think you're ready for paint...?
Post by: Randy Powell on March 12, 2015, 02:35:21 PM: I hope to be ready for paint in under a month. But I won't use primer. Just many coats of clear. Perhaps a tiny bit of zinc sterate in it to eliminate those pesky pinholes.
Title: Re: You know that point when you think you're ready for paint...?
Post by: Mark Scarborough on March 12, 2015, 07:58:11 PM: I hope to be ready for paint in a couple weeks,, maybe,, especially since its not a german plane,,
y1
Title: Re: You know that point when you think you're ready for paint...?
Post by: Howard Rush on March 12, 2015, 08:30:44 PM: Quote from: wwwarbird on March 10, 2015, 08:24:08 PM
...and you shoot a nice primer basecoat only to discover a bazillion tiny pinholes in the wing covering? I'm there. HB~>

I hope the holes are merely from a paucity of dope, rather than whatever nasty stuff was on the wheel pants I've been trying to paint for five years.
Title: Re: You know that point when you think you're ready for paint...?
Post by: wwwarbird on March 12, 2015, 08:43:07 PM: Depending on how I look at it, I think I may have actually gotten sort of lucky here. I've never bothered using primer before, I usually just go from clear prep right to the color coats. I've never had a pinhole problem quite like this before either though, must have gotten ahold of some crap covering. Since this model will have yellow wings and tail surfaces I decided to give the Brodak White Primer a try, so I'd have a light colored basecoat for under the yellow. I figured the primer would cover better for a base than white dope, which it definitely did. If I would have done my normal "right to color" routine I'd now have to be fixing the yellow dope which doesn't sand and fill as easily as the primer. In this case, since it's at this primer stage, I think it might be a somewhat easier fix. I haven't had a chance to get back to it yet, but I will very soon and I've got a couple ideas to try. Fingers crossed...
Title: Re: You know that point when you think you're ready for paint...?
Post by: Howard Rush on March 13, 2015, 01:11:59 AM: I have concluded that if one wants to make an airplane yellow, yellow dope is not the best way to do it.
Title: Re: You know that point when you think you're ready for paint...?
Post by: Randy Powell on March 13, 2015, 11:35:00 AM: Hehe. Yea, there are ways to get yellow that don't include actual yellow.
Title: Re: You know that point when you think you're ready for paint...?
Post by: wwwarbird on March 13, 2015, 06:30:01 PM: Quote from: Randy Powell on March 13, 2015, 11:35:00 AM
Yea, there are ways to get yellow that don't include actual yellow.

Really? What's that recipe?
Title: Re: You know that point when you think you're ready for paint...?
Post by: wwwarbird on March 15, 2015, 08:29:39 PM: Well, my Band-Aid idea pretty much worked out. I needed/wanted to figure out how to fix this problem without adding more weight. I ended up taking a small model brush with 50/50 clear/thinner and worked each pinhole area until the primer softened enough that I could kind of "smear" the hole shut. At the same time I also smoothed each spot out with the brush as much as possible. Each area that I worked on had anywhere from one to a half-dozen or so pinholes. After letting it all dry overnight I came back and carefully feathered everything back in with 600 and 800 sandpaper, dry. I didn't bother counting, but there were probably 150 individual areas that got this treatment.

So, the yellow is on now and it looks good. After letting it dry and looking closely I still have a few pinholes here and there but they are very small, almost undetectable. I'm planning on continuing as normal from here on the rest of the finish, I'm confident that by the time the final clearcoats are on that the pinholes will fill in and disappear. That's the current plan anyway...
Title: Re: You know that point when you think you're ready for paint...?
Post by: Randy Powell on March 16, 2015, 05:31:29 PM: Pete Peterson gets yellow planes by spraying lime gold candy colors on polyspan over balsa. The balsa color turns it bright yellow.
Title: Re: You know that point when you think you're ready for paint...?
Post by: wwwarbird on March 16, 2015, 05:41:53 PM: Quote from: Randy Powell on March 16, 2015, 05:31:29 PM
Pete Peterson gets yellow planes by spraying lime gold candy colors on polyspan over balsa. The balsa color turns it bright yellow.

Sounds fancy, and expensive. I wonder what shade of yellow that ends up being, I'd expect that it varies depending on how far you go with it. In my case here I was after a true Cub Yellow, or thereabouts.

Thanks for the info though. y1
Title: Re: You know that point when you think you're ready for paint...?
Post by: Randy Powell on March 17, 2015, 02:55:59 PM: In Pete's case, bright yellow (but transparent). For Cub yellow, I'd go with a thin coat of white then the yellow.