saramos

2 oz cloth is way too heavy. Pedro is correct in recommending .5 to .75 oz cloth. The purpose of the cloth is not for strenght, but it does add some. The purpose is to give a stable and smooth base for finishing the plane.
I use West Systems epoxy. It gives great results, but is one of the more expensive choices. Be sure to pay attention to the mixing instructions as epoxies vary in the ratio of resin to hardener. As the resin and hardner mix, it creates an exothermic reaction, it will generate heat and then that heat will accelerate the reaction too. If you mix a large amount in a confined container, it can generate significant heat, becoming hot to the touch, and greatly reducing the working time. The brand I use also sells pump dispensers for their cans which will pump out the proper proprtions of resin and hardener. It pumps out about 1.5 oz per pump. I always mix 1 pumps worth at a time and get it onto the plane quickly and spread it out. This will give the most working time. When mixing, once it looks mixed, continue mixing for that amount of time again. I mix up new batches as I go. Always use new containers to mix the new batches. If you mix a new batch in a used container, the older resin can decrease the working time or become gooie. I use a small plastic scraper to spread it out. Fake credit cards that come in the mail works well. Work from the back of the plane forward, top to bottom. that way all overlaps will be away from the air flow. Each section, I work from the center, outward to avoid wrinkles. I like to take off the excess resin by rolling a roll of toilet paper in the direction that prevents the toilet paper from unrolling. Then tear off the outer layer and keep working. The glass will have a slightly dull finish and the areas with excess resin will still look fully wet. This produces a light finish. Some like to use epoxy to fill the texture of the weave. I prefer using high build sandable primer, sanding back to the very top of the weave between coats. If you decide to go with polyester resin, be sure to use lots of ventilation. It's cheaper, and easier to sand, but more hazardous. Epoxy resins are not as volitile but are harder to sand. That, and weight are the two reasons I like to remove as much of the excess when applying. You can also thin with denatured alcohol, but don't use rubbing alcohol as is contains water. Alcohol can extend the working time a little, but can increase the cure time and may remain a bit gummy, sometimes for a long time. I woudn't thin any more that 25% with alcohol by volume.

Cprl_lilhorn

Scott and Pedro,

Thank you for the awesome input! I think I will end up using water based poly and .5oz fg for the bird. Scott, like you I plan to use a primer to fill the weave of the fg. I may add one extra coat of poly because I think it will absorb into the balsa more than epoxy would.

On another note, have you guys ever used lightweight balsa filler instead of microballoons to make epoxy fillets more sandable? I tried this method today and it seems to work fine! First I tested with 6 minute epoxy and made a fillet on two glued-together sticks as a test. With the six minute epoxy it reacted very strangely: it expanded after activation almost like spray foam! I tried another test with 30 min epoxy and got no such reaction. Any thoughts on this? I used the filler-thinned 30min epoxy to create the initial small fillet between stab and fin as I was mounting the fin. Still will blend the parts with wood filler as described in the manual.

M

saramos

I've not tried polyurethane as a subsitute for epoxy, but a lot of people use it and like it. You might try using a light coat sanding sealer first on the bare balsa. I've heard of a couple of people having problems with straight poly u on balsa soaking in enough to cause the balsa to swell and warp. If you haven't alread (which it sounds like you have), do a search here on RCU and you can find some good info on using poly.

Be sure to post photos.

Scott

bigtim

My Feedback: (13)

when I finished mine I used brush on DEFT satin lacquer as a sealer for the balsa before the WB poly, the brush on took more time and was pretty smelly.

now I have been using the DEFT that comes in a spray can, it coats the surface faster so your exposure time is shorter,

I do 2 coats and it seems to be lighter in weight also,after it dries it sands really smooth with a 3M sanding pad, not the sponge, but the thin pad.

another thing is the thicker the balsa sheeting the less sealer you need,I have done 3/32 sheeting with no sealer with no warping but its better to just seal the wood just in case.

its the thin wing skin that can be affected by the water in the poly and can get a warped ripple,my preferred poly is Varathane Diamond satin, it applies quickly and can be recoated within a hour, I do 2-3 coats let it sit over night sand with 220, a couple more and its smooth enough to paint after another light sanding, sometimes it takes a final 6th coat to completely cover the weave but 5 usually gets it done.

the spit and the P-47 are done with WB poly and fully painted(no stickers)for the insignia's.

Cprl_lilhorn

Tim and Scott,

Thanks so much for the input. It's amazing how helpful everyone is on this thread, and on RCUniverse forums in general.

Tim, GORGEOUS planes!! I hope my Spit looks half as good as yours. I plan to paint everything as well, no decals. I'll use Deft or another similar sealer for sure. I was worried about the swelling WB poly might cause, so this was a great tip! Thanks Tim and Scott!

Tim (and anyone else!), have you tried using a primer to fill the weave of FG instead of using 5-6 coats of poly or epoxy? Personally, I think primer would be easier to sand smooth than poly. I've used a lot of WB poly, never on a plane, but in other woodworking projects.. and it's a b(*#& to sand in my experience. I would have to spend an hour or so just to sand the surface of oak ply on furniture applications enough for it to be ready for another coat. Add in the complex curves and shapes of a Spitfire (oooo baby, elliptical wings!!!!), I think it would take even more time.

I have no problem spending the time and effort on this plane, in fact I have enjoyed being a perfectionist with my build so far. But, if the primer-to-fill-weave method works as well as filling the weave with extra coats of poly, I'd probably prefer sanding primer over sanding epoxy.

Thoughts?

Thank you as always guys! I will be taking pictures over the next week and documenting my experiences in sheeting the fuse and mounting the fin and stab, as well as retract installation.

Talk soon,
Mario


PS: Do any of you live near Georgia? I'd love to see your birds and meet you guys, maybe get some flying tips!

saramos

I agree with you as to the generosity and help that can be found here on RCU. There was a thread some time ago that asked what your favorite tool was. My response was RCU. I know that without RCU, I would not know the things I've learned, and building skills would take so much more time to aquire. My Spitfire was my first build, and Tubig, with this thread made it a very successful build. I owe much of that success to him.

Unfortunately, I live on the west coast just north of Los Angeles. Technically, Northridge is a part of the City of Los Angeles. Also, I am more of a builder than a flyer. I don't think I've flown more than a couple of times in the past couple of years. I do have to rectify that. I just picked up a built Bearcat ready to fly, so I need to throw a new receiver in it and get airborne again. Currently, I'm working on what will be my first scratch build. I'm just finishing up a lot of my research on the F4U-1 Corsair and hope to be making dust soon.

I am a part owner in some town home style appartments north of Atlanta. If I make it out there, it would be great to meet. I've had the pleasure to meet several people that I've met here on RCU, and it's always fun. Most recently, I met the fellow who goes by Tfarmer96, who I met when I was building my Spitfire. We had the opportunity to meet in August in Texas where I was working on a full scale Corsair restoration that is being done by Drew King, another person I met on RCU. Terry came out and spent a day working on the Corsair too. Tomorrow, I'll be meeting up with another RCU friend from Holland who is also working on the scratch build Corsair project too. There are others that I've met too, and it's always enjoyable.

I agree with you that Tims planes look great. He gets great results with the poly. On my Spit, I used poly as a clearcoat on the latex finish I did. I too used the Varithane Diamond satin as a recommendation from Tim. I was quite happy with the latex and poly finish, and will use it in the future too.

Cprl_lilhorn

Scott,

That's great that you've had the chance to work on a full-scale project! Do you fly? It's always been a dream of mine to be a pilot. In any case, if you ever have a chance to be in the Atlanta area, feel free to drop a line and maybe you can come visit the little field we fly on here in Cobb county!

I'm thinking of moving to a new field, because the Cobb county field I fly at now is in a bit of a low spot, with hills topped with tall trees circling it. Can make landing approaches a bit tricky if the wind is going the wrong way, requiring a fast descent. Another field nearby is on top of a hill, which is very helpful in this area due to the quantity of ~100ft tall pines that are native to the area. Having to drop 100+ feet for a landing on a short runway is sketchy with some planes! It's not bad with the planes I currently fly, but for a warbird such as the Spitfire that can require a landing under power, or at least with some airspeed, it'll likely raise the hair on the back of your neck!

Take care,
Mario

bigtim

My Feedback: (13)

Mario you could use primer if you wanted to I found when I applied the first couple of coats of the diamond,I didn't need to get all crazy with the sanding, just enough to knock down the small imperfections in the finish and when the next coat goes on it lays down nice and smooth, the key was to allow the coats ample time to harden at least 24hrs so it gets really hard, the Diamond is a floor finish as well as for furniture, so it gets hard enough that when its sanded it powders up nicely, I wipe the surface with a damp paper towel to get rid or the dust and then hit it again with the next coats.

one thing for sure is use a decent new brush,I used a Corona 2"house painters brush, I am a finisher my self so its what I have around the shop generally,but for models I usually get a brand new one, then just lay it down and let it level out, the biggest mistake made with the poly is to try to brush it smooth, it tends to get ropey , stringy lines that show up in the final finish.

something else I have though of doing is after I brush out the first couple of coats is to spray the last few just to get them nice and smooth, but both of those planes were brushed out for the glassing stage so far it works well enough.

I should add I used auto rattle can primer for the spit, sprayed www.warbirdcolors.com primer for the P-47, they both worked great, but I did the majority of the sanding to the primer coat not the glassing coats, there was also quite a bit of filling with Bondo red spot putty after I primed them the first time.
after filling and sanding, I primed over the major areas, lightly sanded the areas with the 3m pads, wiped them down again, and then sprayed the finish coats,the were done using my very expensive Binks airbrush which took some doing, I have since gotten a larger touch up gun from Home depot that does larger areas really well,I then use the airbrush for the smaller detail work and insignia's,I got the stencils for the roundels, and stars and bars from www.getstencils.com I just sent the sticker sheets to them and they made the stencils up for me

my latest paint adventure is a repaint of my ESM FW190A to match more authentic looking colors and patterns

prgonzalez

Thank you Scott and Bigtim for sharing your knowledge and experience with the different products for glassing and painting your models. This is my seventh model build, but my first warbird build. It is also my first glassed model and first painted model. All I can say is that it takes more time, attention to detail, and effort to build a warbird. It is a lot of enjoyment though.

Yesterday, I re-started the build. I spent great deal of the afternoon fitting the wings in the saddle for leveling the stab with the wing tips. At this moment, it is almost done. I also cut the FG fairing pieces and they are ready for fitting and glueing as soon as I finish with the wing saddle. Lots of work that I am seeing is getting closer to the end. This is the time when I look back and I realize that I have learned tons of new things in building this model. All frustrations and anxiety at the different stages of this building are now feelings of rewarding accomplishment. WOW!!! I can't wait for the emotions I will feel when I maiden this model.

Mario, keep up the pace, and provide more pictures.

Pedro

flyingpasty

Hi everyone from Yorkshire in England .My handle betrays the fact that I lived in the SW (Cornwall) for many years playing music at night & flying by day (home built hang glider too).Just discovered this site .What a load of info to help me start my TF spit mk 1X ! It's taken me ages to work out the bits & bobs & where they are on the various sheets (why can't they just give everything a number W this or F that etc?).I have so many questions apart from the ones that have been answered already on the forum even though I am just starting on the stab ( 4 oz of wood !) No wonder there is a tail heavy problem ! It's easy to say -"build the back end light " but you can only do so much .One oz saved at the rear must equate to about 6 oz at the nose I realise. I've been modelling on & off for60 years ,mostly my own designs recently and being retired now on a patch of land with farmhouseof 36 acres to fly from I now have time to build the one aeroplane that I've never built .Hence the TF spit .Basically ,I don't know just which engine to go for (maybe an RCV 90 )I'll be having the flaps (but much more movement ) and retracts I've just been donated (don't know the make -but are GWS 136GH servo operated) This build will be the culmination of a lifetimes experience .There is a lot of history as to why I just love flying I recently discovered that my Dad I never knew was a pilot during the war years .He was Polish ,but flew with the RAF& USSAF & later on was a test pilot based in Rockwell (UFOs ?) No-one told me anything . Anyway,I digress from the subject although I would love to hear from anyone that might have known his squadron .Ithink he flew "jugs" (got a model one)& that he is of course buried in Arlington cemetery. The name -Major Walter Alexander Sudymont -formerly Wusza .
Great site -Sorry if I drifted off topic .-Back to looking for the elusive stab LE pieces
Myron

prgonzalez

Hi Myron,

Welcome to the TF Spitfire build thread. Everyone here tries to give out tips to others and to gather tips from others too. Feel free to ask, someone will have a good answer for you. Everyone of us building this model at this time have address different construction challenges in various ways. Thus, the source is knowledge is good.

Take lots of pictures on your build and post them here. I did minute changes in the tail pieces that I hope dropped some significant weight in the nose. You are right, a minor change in the tail is a major change in the nose.

Whish you an enjoyable building.

Pedro

flyingpasty

Prgonzalez
Thanks for the reply. So far ,I'm half way through the stab the elevator and the fin and rudder .Using alphatic glue means waiting around a lot as you probably know.Hence three or more things at once.Already I could re write the "destructions" .On page 11 no5, I marked the rib positions on the core ,then glued each rib before checking over the plan for perfect alignment .Hardly any need for pinning and abutting to the TE .Secondly -P 12 no2 re- Tip blocks,the wood grain is different from shown on the plan .Probably doesn't matter but I do like things right (or as designed to be).I must mention that I'm a qualified engineer and my early life was at Rolls Royce Aero Engine Division in Derby where I was always involved with perfection.
It seems to me that their publication dept at TF aren't up to my standard .I did produce 3D cut away perspective drawings of engines for inclusion in technical manuals as well so I feel I'm well qualified to criticise .Anyway I shall keep notes and carry on .When I know how to post build pictures then I will. I'm a complete dumbhead when it comes to all things digital .My brain cell can't cope !
Cheers  Myron

saramos

Welcome to RCU Myron!

Scott

Cprl_lilhorn

Myron,

Welcome! How is the build going? Posting pictures on RCU is (thankfully) quite easy. Once you take your digital picture and save it to your computer, you will see a "Click here to upload images and files!" link on the bottom of the reply window. That pops up a window that allows you to upload multiple images at once.

I've really enjoyed building my TF Spitfire so far, although I'm not quite done. Still need to sheet the wings, frame/sheet the bottom of the fuse, and mount the wings (plus all the electrical and engine mounting, fiberglassing, painting, etc.).

I made a boo-boo when testing my retract fitment. In the left wing, I was testing with the wheels on how they would retract and extend. Foolishly, I didn't read the instructions and trim the struts shorter than the original 6" the manual recommends. So, I had trimmed one too many wing ribs. Anyhow.. I also had the air pressure too high when I was testing the retract action and the damn thing flew into the wing, the wheel snapped the top side of the rib where it made contact. So, I fixed the rib and trimmed the strut to the proper length. I also need to reinforce the retract mount rails a bit more before sheeting.

On another note, the upper fuselage is looking sexy! It's all sheeted, turtle deck mounted, and has had its first round of sanding/filling. I applied some more filler last weekend and it's nice and dry, waiting for more sanding. Unfortunately I have a bad head cold, so I'm not really feeling up to inhaling sawdust! I'll post a more detailed description once I take pictures to upload.

-Mario

flyingpasty

Cprl lilhorn
Well today I managed to build the fin,stab & elevators .It's great to be "real" modelling again using eyeball Mk 1 as a guide to sanding.I love it ! Regarding all things digital then that's another matter.My better half has loaded a lot of photos onto my computer reduced in size to be posted to RCM&E 's forum.That's as far as it has got so far.  If you go to modelflying.co.uk & the forum-look up my album ,then you will see an assortment of my efforts including the Spit as of yesterday .My Thread contributions are under my name of Myron Beaumont Just click on albums .
Hopefully get pictures onto this site soon .Back to the balsa dust !

Cprl_lilhorn

Hey Myron,

I'll have to check out the pictures for sure! The Spitfire is a really fun build. I've got to get my pictures taken of the upper fuse and the work I've done on my retract installation so far. Still feeling under the weather, so it might have to wait until next weekend. I kind of messed up on the turtle deck, didn't make it long enough. So yesterday I shaped a small piece to extend past the aft-most former to the leading edge of the fin. Seems to fit OK, and after I install the dorsal fin I'll be blending all the parts in with balsa filler anyhow.

Enjoy the build! Checking out your photos now.

Mario

prgonzalez

Hi y'all

It is good knowing that everyone is progressing on their builds. Myron, I share your joy as I have experienced the excitement of my build too.

I did my part too, I finished the horizontal aligment of the wings relative to the stab. I did this by adjusting the saddle on only one side of the fuselage. As you sand one side of the saddle, the wing will reposition itself horizontally relative to the stab and the other side will reposition too. Initially, I sat the fuse on a piece of foam inside the garage floor. Put a level on the motor box to have it leveled to the floor. As expected, each side of the stab measured the same height to the garage floor. Then, measuring the wing tips height, one wing tip was lower than the other. About 1/2" difference if I recall correctly.

We all hope for perfection, but that is not always achieved. In the perfect world, the wings would have been level relative to the floor too. I believe that one side of the wing does not have the same dihedral angle as the other. We need to remember that one fraction of deviation in the center is amplified at the tips of the wings due to the distance, that is the lenght of the wing. Therefore, I started adjusting the wings horizontal position by sanding the saddle on the side where the wing tip was closer to ground. This repositions the wing higher and at the same time lowers the other side because the fuselage becomes a pivot point of the wing. The help on this, I had to enlarge one of the dowell holes in former 1. This would be locked later by installing doubler C1 in former 1.

After several measurements and adjustments, I got it to my satisfaction. Well, maybe a difference of less than 1/16" between tips. Then, I called it good. It took me around 20 rounds. At the end, the saddle was reduced in about 1/32". I was impressed that a minute sanding in the saddle caused big changes in the wings horizontal position. Then with the wings in position and all measurements confirmed, I proceeded to glue doubler C1 onto former 1 in place. To prevent any shifting, I clamped C1 to former 1 before removing the wings.

What is next is, I will fix the enlarged hole in former 1 to match the hole in C1. Thus, completelly locking the wing's position. If I leave former 1 hole as is, the dowell will only be supported by C1 (1/8") and not by C1+former1 combo (3/8"), causing enlargement of the hole in the future. After locking the wing at former 1, I will proceed to install the lite-ply fairing bottom on the fure and complete the fairing sides and back.

Mario, did you check the incidence of the stab when you glued it? Remember, this is critical on this build.

Pedro.

prgonzalez

Myron,

I checked your three photos on RCME. Also saw your other albums. Nice collection of models and nice work.

Pedro

Cprl_lilhorn

Pedro
No I didn't check the incidence of the stab before gluing. Thought others had found the stab saddles were very accurate. How should I go about checking this with only half the fuse built?

Mario

prgonzalez

Mario,

Being at half fuse build is the best time to check for incidence and make corrections if necessary. If you look back on my postings (photos), you will see how I checked mine before glueing the stab. That was for finding the exact position of the stab and adjusting the saddle to the curvature of the stab for the best possible contact surface without altering the incidence.

I say it is the best time because the half fuse bottom (or building board surface) will serve you as the thrust line or incidence 0° reference line. The stab should measure very close to +2° (up) in reference to your building board.

Pedro

Cprl_lilhorn

Pedro,

Thanks for the info. I'll buy an incidence gauge and check it out before going forward with construction. Worst case, I think I could somehow cut the stab off the fuse (please God don't let it be off!!) and adjust. Any recommendations for a good, easy-to-use incidence gauge?

M

prgonzalez

Mario,

I have a Great Planes laser incidence meter but it is discontinued now. Robart has one that is available. Hangar 9 has another one that it is my understanding uses hard to obtain batteries.

Pedro

Michel

Hi

Get the Robart ,................... I have the Hanger-9 ,................. I don,t trust it ,.......... Period . And the Robart doesn,t need battery's , what you read on the Robart , " IS " what you have .

Michel

flyingpasty

Hi Y'all
Well ,I've finished the tail feathers ready for final sanding on completion.Onto the wings .Rib reinforcements attached to ribs .Sorted out all the bits & bobs and well acquainted with the plans now . My first question is to do with retracts .I've read most of this forum (& many others) for guidance as they will be a  first . A friend of mine sent me a pair of retracts for nothing! After researching the web for some considerable time,it turns out they are David Brown Southern Pro jobs & that they are well respected(aircraft quality etc).Has anyone any thoughts / experience on their use -I got a servo as well to match -GWS 136GH.They will fit the bearers as per plan so am building the wings as per plan .Servo fitting I'll work on as and when .The plan says bend the fixed U/C legs to their shape shown ! I don't think so .All I'll need is a length of 3.5 mm piano wire OR could you recommend any fancy legs that will look & work & fit right ?
Myron

prgonzalez

Myron,

I am using Robarts as recommended by GP and I did not bend the wires. I believe the intention is to project the wheels toward the front to diminish nose over effect, specially when flying out of grass fields.

I checked the angle of my retracts and it seems to be okay in my opinion. I'll see when I maiden her. Anyways, I fly on concrete runway.

Pedro