wdoubleday
Registered User
Fellow Buiders,
some updates from the Javron Cub shop in Snohomish WA. Since my forray into learning how to cover with the Stewarts System back in Jan, and numerous brushes, containers, clothing covered in blue-green glue, I’ve now got the tail surfaces and fuselage covered and just starting to shoot my final color scheme.
Some observations on my learnings:
Follow the instructions! Gee, who would have thought?!
I foam brushed the first 2 coats of Ekofill on the covered parts, then spent a fair amount of time using 320 grit sandpaper to smooth out the pinked tape edges and remove any runs of the Ekofill. I did have to go back with the small iron to re-adhere the tape edges as the Ekofill amplifies anything sticking up. I then shot 2 coats of Ekofill - just on the tail parts so far. I sanded in between coats, mostly focusing on trying to blend in the pinked tape edges.
Shooting the Ekofill went OK, but I had a continuing problem of the gun getting starved for primer. I am using a Devilbiss finishline 4 with a 1.8 mm tip. All other air parameters were according to instructions. I just figured that the carbon solids were settling out in the gravity feed cup, amd eventually clogging the feed channel. I poured out the Ekofill, ran water through gun, then refilled with primer and continued. Spoke with Stewarts but no defined root cause. Anyone else experience this?
Since my base color is sport yellow, I’m glad I decided to shoot 2 coats of white Ekoprime over the Ekofill. This stuff sands like spackle and really helps fill in any uneven surfaces. I tried using the iron to push down some small bubbles, but the heat lifts it right up, so not good. On my horizontal stabs, I had sanded through the white Ekoprime down to the Ekofill on some high spots, then tried to shoot the yellow color. Big mistake! Guess what I’m having to reshoot? I would get full color saturation on the white, woth the dark grey still showing through. After that learning, I shot the rudder which had no darker Ekofill showing through. I shot 4 fog coats, switching between horizontal and vertical passes. Big learning here is do not shoot the tapes first, then fog coat the entire surface. This causes uneven color saturation. You really have to sneak up on the gloss. Another learning is tight gun control to avoid tiger striping. The fog coats are rapid passes with good overlap and gun around 12 inches from surface. I let it tack up for 5 minutes in between fog coats. I then shot two gloss coats with slower gun passes and around 6-8 inches from surface. You have to look behind your gun pass to see the gloss emerge.
Below is my finished rudder and the Quincy compressor I purchased. This is the 5 hp, 60 gallon model which is rated at 15.7 cfm at 90 psi. I hard piped in a manifold with downdrop leg for water drainage. I am using the Camair filter and drying system. Got the Devilbiss 5-Stage system by Camair from Amazon for $600. This includes the regulator. I got the compressor from Nothern Tools for around $1300 with shipping. It’s not inexpensive, but you really do need alot of air moving through gun to shoot waterbourne paints, and dry!
i had one of those moments that are all too rare when you build an airplane. Took the rudder from my shop, sat it on the couch, and enjoyed a cup of coffee whilst admiring an accidental success!
sorry for the long post, but hopefully someone will find this helpful info. Back to the shop for me!
some updates from the Javron Cub shop in Snohomish WA. Since my forray into learning how to cover with the Stewarts System back in Jan, and numerous brushes, containers, clothing covered in blue-green glue, I’ve now got the tail surfaces and fuselage covered and just starting to shoot my final color scheme.
Some observations on my learnings:
Follow the instructions! Gee, who would have thought?!
I foam brushed the first 2 coats of Ekofill on the covered parts, then spent a fair amount of time using 320 grit sandpaper to smooth out the pinked tape edges and remove any runs of the Ekofill. I did have to go back with the small iron to re-adhere the tape edges as the Ekofill amplifies anything sticking up. I then shot 2 coats of Ekofill - just on the tail parts so far. I sanded in between coats, mostly focusing on trying to blend in the pinked tape edges.
Shooting the Ekofill went OK, but I had a continuing problem of the gun getting starved for primer. I am using a Devilbiss finishline 4 with a 1.8 mm tip. All other air parameters were according to instructions. I just figured that the carbon solids were settling out in the gravity feed cup, amd eventually clogging the feed channel. I poured out the Ekofill, ran water through gun, then refilled with primer and continued. Spoke with Stewarts but no defined root cause. Anyone else experience this?
Since my base color is sport yellow, I’m glad I decided to shoot 2 coats of white Ekoprime over the Ekofill. This stuff sands like spackle and really helps fill in any uneven surfaces. I tried using the iron to push down some small bubbles, but the heat lifts it right up, so not good. On my horizontal stabs, I had sanded through the white Ekoprime down to the Ekofill on some high spots, then tried to shoot the yellow color. Big mistake! Guess what I’m having to reshoot? I would get full color saturation on the white, woth the dark grey still showing through. After that learning, I shot the rudder which had no darker Ekofill showing through. I shot 4 fog coats, switching between horizontal and vertical passes. Big learning here is do not shoot the tapes first, then fog coat the entire surface. This causes uneven color saturation. You really have to sneak up on the gloss. Another learning is tight gun control to avoid tiger striping. The fog coats are rapid passes with good overlap and gun around 12 inches from surface. I let it tack up for 5 minutes in between fog coats. I then shot two gloss coats with slower gun passes and around 6-8 inches from surface. You have to look behind your gun pass to see the gloss emerge.
Below is my finished rudder and the Quincy compressor I purchased. This is the 5 hp, 60 gallon model which is rated at 15.7 cfm at 90 psi. I hard piped in a manifold with downdrop leg for water drainage. I am using the Camair filter and drying system. Got the Devilbiss 5-Stage system by Camair from Amazon for $600. This includes the regulator. I got the compressor from Nothern Tools for around $1300 with shipping. It’s not inexpensive, but you really do need alot of air moving through gun to shoot waterbourne paints, and dry!
i had one of those moments that are all too rare when you build an airplane. Took the rudder from my shop, sat it on the couch, and enjoyed a cup of coffee whilst admiring an accidental success!
sorry for the long post, but hopefully someone will find this helpful info. Back to the shop for me!
