Sig Koverall
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RE: Sig Koverall
Thanks, that sound like a great idea.
I guess it is time to start glueing parts on the bird permenantly.
It will be interesting to see what is ready to fly first, my Hog Bipe or the F-22 Raptor ARF that I have on order.
The engine is broken in for the Hog and it should be tuned by the end of the week.
The covering should be going on the Hog starting this week or this weekend.
The F-22 should be at the LHS "early" this month per the owner. I don't even have an engine for it yet though.
I guess it is time to start glueing parts on the bird permenantly.
It will be interesting to see what is ready to fly first, my Hog Bipe or the F-22 Raptor ARF that I have on order.
The engine is broken in for the Hog and it should be tuned by the end of the week.
The covering should be going on the Hog starting this week or this weekend.
The F-22 should be at the LHS "early" this month per the owner. I don't even have an engine for it yet though.
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RE: Sig Koverall
Krylon over Polycrylic over butyrate. Koverall has held up well and am prepping for the clear gloss polyurethane Minwax as a sealer.
The Robin isn't quite completed but I'm quite pleased with the painting portion...
PM
The Robin isn't quite completed but I'm quite pleased with the painting portion...
PM
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RE: Sig Koverall
ORIGINAL: ag4ever
So, when is the best time to drill for hinge-points?
I am ready to sand the model to get it baby bottom smooth, but should I go ahead and hinge the control surfaces now, or wait till it is covered. I plan to wait until it is covered to glue them on, but what about just drilling the holes?
Right now, I am inclined to wait until it is covered and painted to actually drill the holes.
So, when is the best time to drill for hinge-points?
I am ready to sand the model to get it baby bottom smooth, but should I go ahead and hinge the control surfaces now, or wait till it is covered. I plan to wait until it is covered to glue them on, but what about just drilling the holes?
Right now, I am inclined to wait until it is covered and painted to actually drill the holes.
I kind of lost track of this thread; I have the WACO covered and primed, and started shooting color the other day. I had a bit of problem with some pinholing on portions of the wing, but another coat of primer took care of it. Stickbuilder is probably correct; his method (and the time-honored one) of doping the framework before laying the fabric would allow dope to work into the fabric from both directions, likely minimizing pinholes. I've done mine the same way every time, and it seems like there's no rhyme or reason as to why I get pinholes one time and not another. Thinning the first coat or two might help, but it will require more coats to fill the weave that way The finish on my UMF will probably be my best result yet, if the newly painted elevator is any indication.
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RE: Sig Koverall
How is Koverall versus say Skyloft? I'm working on a scratch built Ugly Stick and dont want iron on covering. It's my first build in about 20+ years. I never used monokote. I always used good ole silk and dope.
I cant remember as far as prepping goes, do the wing ribs need to be rounded a bit? I assume they should not be round but the sharp edges should be broke off????
I cant remember as far as prepping goes, do the wing ribs need to be rounded a bit? I assume they should not be round but the sharp edges should be broke off????
#60
RE: Sig Koverall
OK guys, I've read this whole thread and I can't thank all y'all enough for the incredible amount of information you've given me here.
I'm restoring a 45 year old plane, Scale Lines model (kitted in 1961) of the 1931 Great Lakes 2T-1A and some of the challenges I've faced (never worked a biplane, never flown a biplane) have been quite more than enough for this old man. When I started the restoration I knew that I wasn't going to monokote it (was originally covered with silkspan & dope), didn't want to spend the $$ for silk, but definitely wanted a "material/fabric" covering.
It's looking like Koverall is going to be my choice - I like most everything I've read here about how it works and I definitely like how it looks. Got one more minor question though for you guys before I go out and buy my finishing materials. This will be my first Koverall and first Nitrate-clear project, and I've been building/flying for more than 50 years.
When I stripped off the original covering (much of it simply flaked off in little bits & pieces) the entire nose section (solid wood), actually, much that is "solid" wood was found to be pretty much unremovable. I've sanded the beejeebers out of this critter (mostly 200-grit paper) and it simply "ain't comin' off". I know that butyrate clear would stick (and I still have about a half quart from my last project), how about the nitrate clear? Or should I get some more butyrate clear for the nose section?
I'm still working the engine compartment right now but covering-time isn't very far off at all and I'm getting "itchy" to fly this critter anyway. There have been at least 2 engines in her in the past (one was definitely an "ignition" type, wires were still there) and I've had to go quite a ways in carving and re-carving and then rebuilding the interior so I can fit a new OS-40 into her, upright with a pitts-style muffler (can be seen under the plane in one of the pics below) imbedded in the side, exhausting to the right. The nose is off her right now, while I'm routing out a bed for the new plate-style engine mount.
Dave
I'm restoring a 45 year old plane, Scale Lines model (kitted in 1961) of the 1931 Great Lakes 2T-1A and some of the challenges I've faced (never worked a biplane, never flown a biplane) have been quite more than enough for this old man. When I started the restoration I knew that I wasn't going to monokote it (was originally covered with silkspan & dope), didn't want to spend the $$ for silk, but definitely wanted a "material/fabric" covering.
It's looking like Koverall is going to be my choice - I like most everything I've read here about how it works and I definitely like how it looks. Got one more minor question though for you guys before I go out and buy my finishing materials. This will be my first Koverall and first Nitrate-clear project, and I've been building/flying for more than 50 years.
When I stripped off the original covering (much of it simply flaked off in little bits & pieces) the entire nose section (solid wood), actually, much that is "solid" wood was found to be pretty much unremovable. I've sanded the beejeebers out of this critter (mostly 200-grit paper) and it simply "ain't comin' off". I know that butyrate clear would stick (and I still have about a half quart from my last project), how about the nitrate clear? Or should I get some more butyrate clear for the nose section?
I'm still working the engine compartment right now but covering-time isn't very far off at all and I'm getting "itchy" to fly this critter anyway. There have been at least 2 engines in her in the past (one was definitely an "ignition" type, wires were still there) and I've had to go quite a ways in carving and re-carving and then rebuilding the interior so I can fit a new OS-40 into her, upright with a pitts-style muffler (can be seen under the plane in one of the pics below) imbedded in the side, exhausting to the right. The nose is off her right now, while I'm routing out a bed for the new plate-style engine mount.
Dave
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RE: Sig Koverall
Gents,
Here is what I am doing with Koverall. My father got me started with silk before monocoat. I used to dope on the cover (wet) and then begin the finishing process. My wife and I just can not stand the smell any more so I have gone to latex products and they seem to work as well as the dope did. I am using a product from Michael's Craft Stores called Modge Podge. It is a sealer/adhesive. First seal the wood with a 50/50 mixture of water and MP, light sanding when dry and then one more coat. Cut Koverall a bit oversize, lay over area to be covered and using a foam brush apply the 50/50 mix to attatch the covering. Let dry. After dry you can use a Monocoat Iron to secure the edges. Another thin coat of 50/50 around the edges and let dry. When dry trim with a sharp blade and use the iron again to secure the coverings edges. Cover other side overlaping as much as possible. This system is a lot easier than it sounds ad moves along rapidly. After covering both sides shrink and begin applying 50/50 to seal the weave. About three coats. Ready for primer and paint, latex of course. No sanding as this raises hairs.
JEB
Here is what I am doing with Koverall. My father got me started with silk before monocoat. I used to dope on the cover (wet) and then begin the finishing process. My wife and I just can not stand the smell any more so I have gone to latex products and they seem to work as well as the dope did. I am using a product from Michael's Craft Stores called Modge Podge. It is a sealer/adhesive. First seal the wood with a 50/50 mixture of water and MP, light sanding when dry and then one more coat. Cut Koverall a bit oversize, lay over area to be covered and using a foam brush apply the 50/50 mix to attatch the covering. Let dry. After dry you can use a Monocoat Iron to secure the edges. Another thin coat of 50/50 around the edges and let dry. When dry trim with a sharp blade and use the iron again to secure the coverings edges. Cover other side overlaping as much as possible. This system is a lot easier than it sounds ad moves along rapidly. After covering both sides shrink and begin applying 50/50 to seal the weave. About three coats. Ready for primer and paint, latex of course. No sanding as this raises hairs.
JEB
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RE: Sig Koverall
Yes it can. I would use a latex glue as I did. This way you can be sure the glue is compatable with the foam in case the glue leaks throught any holes in the balsa. I would also use a latex filler such as I did or Polyacrylic for the same reason.
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RE: Sig Koverall
BPS, please tell me more about the modge podge and fabric covering method. i am about to recover a 1/4 scale cub and would love to find out that the dress liner poly fabric and MP would work well enough to use on my new, sweet airplane! both of these materials are locally available and the koverall and dope are far from being easily found.
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RE: Sig Koverall
I have not used dress lining myself although I have read accounts of others that have been successful. Heat shrink polyester is the important part. Years ago the full scale folks used cotton, but I would not suggest that. Here is what I do with the ModPodge available from Craft Stores such as Michael's. When the model is completed and sanded ready to cover;
1) Coat entire framework with ModPodge using a foam brush.
2) Light sanding using at least 400 or finer.
3) Second coat of ModPodge if needed, most of the time mine do not need this step.
4) Cut fabric with at least 2" overlap. I cover one side at a time. Wing=bottom, Fuse=side or half if it is round and so on.
5) Lay fabric on surface and brush through thinned ModPodge with a foam brush. MP thinned to a consistancy that will allow it to penitrated the fabric but not puddle under it. I use tap water.
6) After this drys I use a Monocoat iron on low temp settings to work any spots on the fabric that did not adhere. Sometimes I add more MP and then let it start to set up and then use the iron. Clean iron with Denatured Alcohol.
7) Another coat of thinned MP and iron down the edges. Trim with a hot or sharp knife and smooth down edge with iron.
8) Cover other side and overlap fabric about 1", repeating above steps.
9) Shrink fabric.
10) Fill weave of fabric with thinned MP being careful that it does not puddle underneath. Takes about three coats.
11) Light sanding with 800-1000 grit and your ready for paint. NO STINK!!!!!!
Be careful these are water based products and can induce a warp in light or weaker structures. You may have to weight some of the ligher structures down to prevent this although I have not had to. Love this process and did I mention no stink and no toxic fumes!
Let us know your thoughts if you decide to try this.
1) Coat entire framework with ModPodge using a foam brush.
2) Light sanding using at least 400 or finer.
3) Second coat of ModPodge if needed, most of the time mine do not need this step.
4) Cut fabric with at least 2" overlap. I cover one side at a time. Wing=bottom, Fuse=side or half if it is round and so on.
5) Lay fabric on surface and brush through thinned ModPodge with a foam brush. MP thinned to a consistancy that will allow it to penitrated the fabric but not puddle under it. I use tap water.
6) After this drys I use a Monocoat iron on low temp settings to work any spots on the fabric that did not adhere. Sometimes I add more MP and then let it start to set up and then use the iron. Clean iron with Denatured Alcohol.
7) Another coat of thinned MP and iron down the edges. Trim with a hot or sharp knife and smooth down edge with iron.
8) Cover other side and overlap fabric about 1", repeating above steps.
9) Shrink fabric.
10) Fill weave of fabric with thinned MP being careful that it does not puddle underneath. Takes about three coats.
11) Light sanding with 800-1000 grit and your ready for paint. NO STINK!!!!!!
Be careful these are water based products and can induce a warp in light or weaker structures. You may have to weight some of the ligher structures down to prevent this although I have not had to. Love this process and did I mention no stink and no toxic fumes!
Let us know your thoughts if you decide to try this.
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RE: Sig Koverall
i am so happy to see that covering procedure layed out like that! it is much easier to understand than searching through countless threads to locate info like that. i bought some fabric last night to test and i plan to try it tonight after my wife goes to sleep!
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RE: Sig Koverall
Hello JEB,
I just finished working through your ModPodge process on a disposable wing half from a buddy's crashed ARF.
Thanks for posting your method, and giving me a starting point.
I am using 100% polyester dress lining from the craft store.
The material weighs 4.4g/sq ft and shrinks fine.
I am using a disposable HD foam brush to apply the ModPodge thinned to a "milk" consistency.
The weight is piling on fast, and I haven't even started putting color on.
I am heading for a finished density of 16g / sq ft, about twice that of a Monokote finish!
See the enclosed spreadsheet for measured weights, normalized to g / sq ft.
A handful of topics I would like to discuss:
1. I am having a lot of trouble filling the weave evenly without leaving streaks/blotches. These would show through the color if I were to proceed with the wing as it is.
1a. Can this be fixed with another brush coat?
1b. Have you tried spraying this stuff?
2. Is There an effective way to seal the wood at the beginning, so I can avoid soaking a ton of glue into the wood surface? Have you tried using a sanding sealer?
3. How long does the ModPodge need to cure before it stops feeling tacky?
4. Do you have experience spraying latex finishes on this surface? Do you recommend a primer, or can I go directly to the color coats?
I just finished working through your ModPodge process on a disposable wing half from a buddy's crashed ARF.
Thanks for posting your method, and giving me a starting point.
I am using 100% polyester dress lining from the craft store.
The material weighs 4.4g/sq ft and shrinks fine.
I am using a disposable HD foam brush to apply the ModPodge thinned to a "milk" consistency.
The weight is piling on fast, and I haven't even started putting color on.
I am heading for a finished density of 16g / sq ft, about twice that of a Monokote finish!
See the enclosed spreadsheet for measured weights, normalized to g / sq ft.
A handful of topics I would like to discuss:
1. I am having a lot of trouble filling the weave evenly without leaving streaks/blotches. These would show through the color if I were to proceed with the wing as it is.
1a. Can this be fixed with another brush coat?
1b. Have you tried spraying this stuff?
2. Is There an effective way to seal the wood at the beginning, so I can avoid soaking a ton of glue into the wood surface? Have you tried using a sanding sealer?
3. How long does the ModPodge need to cure before it stops feeling tacky?
4. Do you have experience spraying latex finishes on this surface? Do you recommend a primer, or can I go directly to the color coats?
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RE: Sig Koverall
[quote]ORIGINAL: martyg
Hello JEB,
I just finished working through your ModPodge process on a disposable wing half from a buddy's crashed ARF.
Thanks for posting your method, and giving me a starting point.
I am using 100% polyester dress lining from the craft store.
The material weighs 4.4g/sq ft and shrinks fine.
I am using a disposable HD foam brush to apply the ModPodge thinned to a ''milk'' consistency.
The weight is piling on fast, and I haven't even started putting color on.
I am heading for a finished density of 16g / sq ft, about twice that of a Monokote finish!
See the enclosed spreadsheet for measured weights, normalized to g / sq ft.
A handful of topics I would like to discuss:
1. I am having a lot of trouble filling the weave evenly without leaving streaks/blotches. These would show through the color if I were to proceed with the wing as it is.
I did not experience this. The weave filled nicely with 2 to 3 thinned coats. Koverall is 1.25 oz per square yard of material http://www.sigmfg.com/IndexText/SIGKV001.html
[b]The material should be applied in thin even coats and allowed to dry completely before brushing on the next coat. Overnight worked for me.
Can this be fixed with another brush coat?
1b. Have you tried spraying this stuff?
Thinned to proper consistancy it will spray like any other latex product. I did not spray mine. The foam brush worked for me.
2. Is There an effective way to seal the wood at the beginning, so I can avoid soaking a ton of glue into the wood surface? Have you tried using a sanding sealer?
You should seal the wood BEFORE putting the fabric on the surface. The unsealed surface will absorb the fabric glue and filler like a sponge. I sealed my wood with ModPodge. You have to be very careful with warpage though. This is a latex product.
3. How long does the ModPodge need to cure before it stops feeling tacky?
4. Do you have experience spraying latex finishes on this surface? Do you recommend a primer, or can I go directly to the color coats?
I use white latex as my primer and base. You could use a sandable primer but this will add weight.
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RE: Sig Koverall
Thanks for the quick response!
I probably should have let the fill coats dry longer before reapplying.
A subsequent coat applied later this morning seems to have flowed and evened out the areas I was worried about.
I did use the ModPodge to "seal" the wood ("Base coat, sanded" step) by brushing an undiluted coat over all exposed wood and allowing to dry.
As you can see from my numbers, the way I did this added as much weight to the part as the fabric itself.
What technique do you use to control the amount of absorption when sealing? Should I wipe it on/off with a rag instead?
I appreciate the guidance,
I probably should have let the fill coats dry longer before reapplying.
A subsequent coat applied later this morning seems to have flowed and evened out the areas I was worried about.
I did use the ModPodge to "seal" the wood ("Base coat, sanded" step) by brushing an undiluted coat over all exposed wood and allowing to dry.
As you can see from my numbers, the way I did this added as much weight to the part as the fabric itself.
What technique do you use to control the amount of absorption when sealing? Should I wipe it on/off with a rag instead?
I appreciate the guidance,
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RE: Sig Koverall
Nice job on all the research. I am somewhat suprised that it added this much weight. The latex stuff is mostly water and as it cures the water is released. I am wondering if you had let each coat dry more if the weight gain would have been less? You could always use the traditional balsa wood sealers but they stink! I have read where others have used hardware store brand wood sealers with success. You can always add density to the filler by adding baby powder. An old trick and it does not take much at all.
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RE: Sig Koverall
Here is the finished product. I am just now finishing up detail work. The paint is acrylic latex from the craft store, base white was sprayed and the blue was brushed on using a foam brush. Topcoated with rattle can Varithane outdoor water based polyurethane. Not fuel proof but ok for gas.
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RE: Sig Koverall
ORIGINAL: khodges
Here's what a Koverall finish can look like. This is Krylon over Rustoleum primer, over nitrate dope (3 coats). I think it's worth a little weight, sure beats MonoKote. This is the Cox/Pica YMF Waco, the "un-ARF'd" version
Here's what a Koverall finish can look like. This is Krylon over Rustoleum primer, over nitrate dope (3 coats). I think it's worth a little weight, sure beats MonoKote. This is the Cox/Pica YMF Waco, the "un-ARF'd" version
Thanks
Lamar
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RE: Sig Koverall
Hi Lamar,
The Krylon will not be Nitro Fuel Proof. I don't think there is a top coat that will fuel proof it either. Someone else may have some ideas there. As far as I know there is not.
I used a similar method but then painted with water based Warbird colors which is fuel proof. I had some trouble spraying the white and black. The blue sprayed well though. I would prefer not to use it again but that's only because I would rather spray latex. Have to go gas engine to do that though.
My results are below.
sean
The Krylon will not be Nitro Fuel Proof. I don't think there is a top coat that will fuel proof it either. Someone else may have some ideas there. As far as I know there is not.
I used a similar method but then painted with water based Warbird colors which is fuel proof. I had some trouble spraying the white and black. The blue sprayed well though. I would prefer not to use it again but that's only because I would rather spray latex. Have to go gas engine to do that though.
My results are below.
sean
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RE: Sig Koverall
Thanks Sean for letting me know about the krylon paint. Do you know of any other type spray canpaint that may be used over the Koverall/nitrate dope prepared finish that is glow fuel proof and readily available.
Lamar
Lamar