Author Topic: Dope slightly darker on one side of wing then the other? (Read 817 times)

Dennis Toth · « **on:** August 31, 2020, 06:33:04 PM »

I've finished covering my electric Ringmaster wing and applied 4 coats of Sig super coat clear. The finish will be a dyed silkspan. The covering went on smooth and is nice and tight. I did one side, give it the 4 coats then covered the other half and gave it the same 4 coats of clear.

I'm seeing the first side is a little darker then the second side. I did the first side outside in the bright sun then set it under the covered poach to gas off. For the second side it was cloudy (still not to high humidity). I'm wondering if the bright sun UV caused the first side to darken a little? Anyone have this happen? Beside painting the whole thing any ideas to get get both sides with the same tint?

Best, DennisT

Ken Culbertson · « **Reply #1 on:** August 31, 2020, 09:59:20 PM »

Is it possible that the dyed silkspan was from different batches? Was it dyed by you or did it come that way? Don't think it was the dope.

Ken

Dennis Toth · « **Reply #2 on:** September 01, 2020, 10:38:58 AM »

Thanks for the input. I dyed the silk span all a the same time. I put a couple more coats of clear and it seems to be evening out. I think I may have thinned the second patch of clear more then the first and it needs a few more coats to get equal coverage.

Weight wise it seems to be only adding about 3/4oz. Silkspan is nice an tight, will switch to lite coat for the final fill coats.

Best, DennisT

Ken Culbertson · « **Reply #3 on:** September 01, 2020, 11:01:12 AM »

Quote from: Dennis Toth on September 01, 2020, 10:38:58 AM

Thanks for the input. I dyed the silk span all a the same time. I put a couple more coats of clear and it seems to be evening out. I think I may have thinned the second patch of clear more then the first and it needs a few more coats to get equal coverage.

Weight wise it seems to be only adding about 3/4oz. Silkspan is nice an tight, will switch to lite coat for the final fill coats.

Best, DennisT

There you go! Never thought about the thinner. One of the most beautiful planes I remember was Dick Mathis's Chizziler with a see through finish. It was in the 60's, think it was yellow and I am pretty sure it was his. I can't use see through. In my case it would be "See Flaws"

Ken

Dennis Toth · « **Reply #4 on:** September 01, 2020, 01:55:25 PM »

Ken,
This was a rescue Ringmaster S1 that originally had a McCoy 35, big heavy Perfect wheels and some kind of Kevlar leadouts that were fraying. I stripped the ship and have found some ways to reduce the weight which originally was 38 1/2oz. I hope to get it under 33 oz. ready to fly electric.

For the transparent finish, one thing the original builder did was spray a coat of white primer on the balsa frame that gave a consistent base to apply the covering. As much as I didn't like that it had this on the frame it actually worked out pretty good. I applied two coats of clear to the frame then covered with the dyed silkspan. It looks great over that white frame and doesn't take away from the dyed yellow silkspan.

Best, DennisT

Ken Culbertson · « **Reply #5 on:** September 01, 2020, 03:17:18 PM »

Quote from: Dennis Toth on September 01, 2020, 01:55:25 PM

Ken,
This was a rescue Ringmaster S1 that originally had a McCoy 35,

Good ol McCoy 35. It is hilarious how that engine's reputation has improved with age. I went through a pile of them in the late 60's. $5.00 at the BX. Treated right they were more powerful than the Fox 35 for about 50 flights. In my circles you were considered pedestrian if you ran a McCoy. Now they are hot items. Probably because the ones that still run them remember the 60's.

Cool idea with the white.

Ken

Dennis Toth · « **Reply #6 on:** September 02, 2020, 06:46:43 AM »

Ken,
The McCoy 35 and later the 40's got a big boost in the stunt community after Ed Southwick won the Nats with one in his Skylark. Seems they ran really good on Super Fuel. The McCoy like the K&B's were more powerful than the Fox 35 but because they had the steel fins/cylinder were about 3/4oz. heavier than the Fox. Once Ed won people started to look at them and boom their a stunt engine. The K&B 45 had a similar boost when Lew McFarland used it for his Shark 45 and won the Nats. Seems as we have moved into a different run style these more powerful engines aren't at such a disadvantage because of their extra weight.

On the dope darkening side - I have some older clear Sig Lite coat dope (like 30 yrs) that has a slight amber tint and I may give the light side one coat to see if that evens it out. Otherwise, I will just do as Ty said and say that's the way I planned it and claim it creates a competitive illusion in maneuvers.

Best, DennisT

Ken Culbertson · « **Reply #7 on:** September 02, 2020, 08:54:21 AM »

Quote from: Dennis Toth on September 02, 2020, 06:46:43 AM

Ken,
The McCoy 35 and later the 40's got a big boost in the stunt community after Ed Southwick won the Nats with one in his Skylark. Seems they ran really good on Super Fuel. The McCoy like the K&B's were more powerful than the Fox 35 but because they had the steel fins/cylinder were about 3/4oz. heavier than the Fox. Once Ed won people started to look at them and boom their a stunt engine. The K&B 45 had a similar boost when Lew McFarland used it for his Shark 45 and won the Nats. Seems as we have moved into a different run style these more powerful engines aren't at such a disadvantage because of their extra weight.

On the dope darkening side - I have some older clear Sig Lite coat dope (like 30 yrs) that has a slight amber tint and I may give the light side one coat to see if that evens it out. Otherwise, I will just do as Ty said and say that's the way I planned it and claim it creates a competitive illusion in maneuvers.

Best, DennisT

Careful with the competative illusion. One thing I have noticed when the top and bottoms are not similar (except for trim) is that they can give the illusion of a flat spot if you are not observing from dead upwind.

I get funny looks when I mention this to some fliers so I will put it here where I can't see the funny looks I will be getting!

Ken

John Leidle · « **Reply #8 on:** September 02, 2020, 09:02:58 AM »

Hi Dennis,
When I used to use Rit dye on my silkspan I found that the first sheet was always darker than the last sheet.
John L.

Dennis Toth · « **Reply #9 on:** September 04, 2020, 05:24:42 PM »

Ok, two coats of the older clear Sig Lite coat dope (like 30 yrs) that has a slight amber on the light side did the trick. Both sides are now very close and will switch to Brodak clear that is only 5 yrs old. So far I have 6 coats on the wing and the grain is just about filled, maybe 3 - 4 coats to complete the clear.

Best, DennisT

Author Topic: Dope slightly darker on one side of wing then the other? (Read 817 times)

Dennis Toth

Dope slightly darker on one side of wing then the other?

Ken Culbertson

Re: Dope slightly darker on one side of wing then the other?

Dennis Toth

Re: Dope slightly darker on one side of wing then the other?

Ken Culbertson

Re: Dope slightly darker on one side of wing then the other?

Dennis Toth

Re: Dope slightly darker on one side of wing then the other?

Ken Culbertson

Re: Dope slightly darker on one side of wing then the other?

Dennis Toth

Re: Dope slightly darker on one side of wing then the other?

Ken Culbertson

Re: Dope slightly darker on one side of wing then the other?

John Leidle

Re: Dope slightly darker on one side of wing then the other?

Dennis Toth

Re: Dope slightly darker on one side of wing then the other?