superworm

Hi Rate1

The fuse has indeed got lightening holes which is why I stated that I would be using SolarTex for covering (the original has textile covering aft of the cockpit). The rest will be glassed (or proskin).

Don't worry about proskins on the wings, it is available in big enough panels. The Aileron servo (and wing attach bolts which go through the joiner tube) will have their bays lines with balsa sheet and with landings for the covers, proskin will perfectly well suffice to make these covers.

Its not so much the glassing that will add weight to the plane. it will be the paint that adds the weight..there must be over a half pound of weight in my ultimate's paintjob....got to look pretty hasn't it ?. For glassing, I use 0.6oz per sq yard (Christian Units!) woven glass with Z-Poxy finishing resin thinned abaout 20% with Methylated Spirits or Denatured Alcohol:

"iron on" the glass with your V.clean hands (should overlap all edges of the wing half by an inch or so), pour on a dollop of resin in the centre of the panel and screed (sqeegee) it away from the centre towards the edges with your credit card until the glass is all wetted through right to the edges so that it drapes vertically over those edges. Add small dollops of resin as needed if your run out as you sqeegee. There should be no "dry" spots (the cloth looks lighter where its not stuck down) and there should also be no "glossy" parts...this indicates too much resin...squeegee it out some more. Don't be too vicious with the credit card...you can "drag" the cloth ...but don't be too soft on either,, you won't remove the excess. When finished squeegeeing, it should sort of consistently matt all over. Leave it overnight (24 hrs preferrably) parked on a support that lets the cloth dangle vertically over the edges and walk away from it til at least the next evening. The excess that dangled over the edges can then be simply removed ny gently rubbing the edges with your sanding bar. Repeat for other side then turn over and do the other sides. Gently sand the whole lot with medium to fine aluminium oxide paper and then give the whole lot (one side a ta time, another coat of thinned epoxy finishing resin to completely fill the weave.....then use wet & dry (wet with a few drops of washing up liquid in the water and it'll soon be ready for priming/finish coating.. dead easy but practice glassing a piece of 1/4 balsa first if you like....don't sand the wing with it on your knees - as noted earlier

More anon

Cheers

Rate1

I read this articel where it states not to do a second epoxy run over the surface. Claiming if one do the second cote it will also give even more weight. Check it out;

http://www.airfieldmodels.com/inform..._panels/04.htm

I guess I simply have to wait and see what weight this bird will land at in its bone. Knowing this will make it easier to estimate the all up weight and then decide what engine I will select followed with what kind of covering job to be applied.

superworm

Hi Rate1

I painted my ultimate with a deVilbiss Airbrush....paint goes on very thin and you can work up the gloss over two or three consecutive coats...just enough paint to just wet out the surface....anymore and you'll get runs!(ouch). Some folks use a "touch-up" gun but the airbrush does it for me..if I went 1/3 scale I'd get such a gun.

Its not a bad idea to wait until the plane is in its bare bones before deciding on covering medium and engine. In the case of the latter we are lucky because of the way in which the firewall is designed. The ngine is mounted on a box structure which can slide in and out of the main firewall so that your prop driver/spinner backplate finishes up the correct position. You don't need to glue this in place until you've decided which engine to use.. I've earmarked my YS140 for this plane but a (methanol) Moki 135 or a big OS twostroke (160?) or even a petrol/gasoline jobbie will do. I hope I can keep the YS within the cowling !

I've read your glassing thread..particularly the glass cloth link. Its pretty much the same as I do it except that my second coat of epoxy is thinned and again sqeegeed to ensure the glass is properly attached to the substrate. Since my first coat is also thinned, I guess we'll have about the same amount of resin...this in turn is rubbed down with wet'ndry used wet (400 to 600 grade) so there is little excess of resin when I've finished and I KNOW my cloth is well stuck down. Not more than a couple of rubbed down coats of primer is all that I need. On the Ultimaye I used Hobbypoxy 2 part paint which is no longer available (Environ-Mental guys killed it off!). We now have paint called Klass Kote to use which, I believe does just as good a job and is more environmentally friendly:

http://www.klasskote.com/

This is available in limeyland/Euroland via Barron paints:

http://www.baronpaints.co.uk/

If you really want lite...go with the film covering...profilm or solarfilm/solarspan. I reckon a film covered plane is worth about 3yrs good usage before it needs redoing...but at least you get to select another scheme. Methinks paint will last forever..my Ultimate is now over 12 yrs old and looks like new except for the odd decal is starting to lift !

More anon..wifey is putting the lights out and I don't want her to see my screen saver...alternates between Patty Wagstaff and (a youngish) Agnetha!

Cheers

Rate1

Superworm,

Cheers for the describtion on how to.

If I had to chose only one I would go for ol Patty,

superworm

hi Rate1

just remebered...there is an alternate to f/g epoxy skinning resin...use acrylic (floor) varnish or use a custom brew from (say) Falcon Aviation from the UK

http://www.123pc.org/fa/index.html?t...tml&lang=en-gb

back to work...later

Cheers

CafeenMan

Rate1 - I am going to update my site because I've decided that if done properly a second coat of resin works better than trying to fill the weave of the cloth (and seal it) with primer. I haven't had time to edit the article yet but my finishes are turning out better and with no more weight than what I was doing when I apply the second coat.

The trick to getting a light painted finish is to use a lot of sandpaper. The first coat of resin should be as little as possible to adhere the cloth. The second coat gets brushed or squeeged back in forth in all directions such that it gets under the weave and seals the wood where the first coat didn't. Excess is removed per usual. There should be no resin above the weave of the cloth.

Sand that coat well but not into the cloth. Now continue with primer coats. Again, you want to spray light coats and sand between coats so that it's barely opaque.

Proper paint application is not heavier than Monokote. People who claim paint is heavy are applying the paint too heavily and not sanding it off. That's their error - not a fundamental problem with paint.

But yes, it's a lot of work and probably not worth it for most sport models.

Rate1

Superworm, too late. Yesterday I picked up epoxy resin from my local boatstore. It states on the instruction that it will be dry to touch in 8 hrs and fully cured in 24 hrs. According to the salesperson it will also be fairy thick in its consistence. I translate that to not being sucked up by the balsa for a lighter weight wich is good.

Rate1

CafeenMan,

Good to hear from you. After been reading the article and then been talking to other guys I realized that I had heard of as many ways of doing glassing as people I asked! Needless to say, it is hard to really figure out wich way is the proper/best way of doing it and then to make a good decission. My biggest concern for the moment, as meantioned erlier on this thread, is to figure out what extra weight a finished fiberglass structure (primed, painted and done properly) has compered to Monocote? I have heard some estimates, for a 72" sportsplane, 0.8 lbs??? Do you agree on that number?
I guess I will have to wait with deciding in what covering this plane will have untill I have a finished structure to estimate its flying weight. However, even at that stage of the build I would need an Estimate weight of both the applications as the end result/flying weight is the one that actually counts. Obviosly I would like to have pretty plane as well this is why I am asking questions about glassing.
You just mentioned that paint is not more weight than Monocote, but I would like to know film covering compered to fiberglassed plane that is primed and painted.

superworm

Hi Rate1

Now you have me worried:::
I'm not too sure if you're doing the right thing here...what you may have from the Boatyard (chandler's) is laminating resin which I believe is a little bit different in chemical make-up from ZAP's Zpoxy type of Finishing resin. My thoughts are that the Thicker the epoxy is, the less likely it is to penetrate through the Glass and into the wood.....what the thinned epoxy resin is doing is indeed being sucked into the wood to properly adhere the glass after which the thinning substance (meths) more or less totally evaporates leaving a very lightweight sparsley populated matrix of the resin remaining..ie not much...in the wood...just enough. If you plaster your laminating resin on unthinned its going to be a devil of a job sanding off the excess and I'd like to suggest a lot of it won't make it through the weave to bond with the wood..which is what you need. Not only that but I would also suggest that it will be very difficult to sqeegee anyway which could easily result in you "dragging" the cloth and disturbing the weave (warp and weft !) leaving gaping holes and bunching of the cloth in your reinforcing....reinforcing is what the resin is supposed to do to the balsa as well as providing you with a relatively hard and smooth surface on which to stick your paint.

Methinks your boat resin is ideal for wing joining purposes IF (and a big IF) it is NOT POLYESTER Resin.. That stuff will gobble up your foamcores faster than a gallon of cellulose thinners (and that is mighty fast)...but you knew that ????

I would also suggest that you get a 36" length of 1/4" balsa, cut it into 3 equal lengths. Cover the first with monocote or other film (oracover/profilm) and weigh it before and after. For the second piece, weigh it bare then cover it with 0.6 oz/sq.yd glass and stick it down with your boat epoxy straignt from the can.. sand it down, prime and paint it as cafeenman suggests. Now do likewise on the third piece with thinned epoxy..thinned say 50% if you use your boat epoxy...sand it down and give it another coat sqeegeed well into the weave. Sand that down and paint it. If you use a chemical balance (like at your olde school science classroom or the local pharmacy).. you'll have the comparative weights/sq. foot and be able to calculate how much difference it will make to your extra and put your mind at ease and give your some practice to perfect your method.

more anon

Cheers

Rate1

Superworm

I got this boat stuff to sheet the foam core not to glass the wing. Perhaps I got the wrong stuff? Do you have an URL (in Europe) for a resin that you know is the correct one? Thia as I can't afford screw this one up just because I am using the wrong stuff...??

That is a good idea to make sample before chosing which covering to use.

superworm

Hi Rate1

You could try one of the UK stockists:

http://www.inwoodmodels.co.uk/system/index.html

goto the drop-down buttons:


materials>>>Glue>>>ZAP

to find the Finishing Resin (+ 5 and 30 min epoxy glues CA's etc).. I'd be surprised if your local model shop can't get it for you...Inwood will charge you postage at cost.

If you're going to use your boat resin for sticking your balsa sheet to the foam cores unthinned you will add an awful lot of weight.. Again I have only ever used thinned Zpoxy finishing resin for this task...you can test this theory by painting some onto a small piece of polystyrene foam and slicing it open when dry to see how far the resin has penetrated...hopefully not at all.

iirc, Sig used to sell a bonding adhesive (Sigbond??)...operated somewhat like Evostick where you spread the stuff on both your cores and skins and then put them together after the glues has dried to the touch....problem with this method is that you only ever get one go so your positioning has to be ok first time. Other folks I know have used 3M "spraymount"..a similar aerosol adhesive for making posters etc. I also know of people who have failed using this method with their skins becoming unbonded..

Another suggestion is to use the ProBond suggested by Mick Reeves for bonding his Proskins...that stuff sticks like the proverbial and you may also get a few secomds to get it positioned OK.

Just a few ideas to get you thinking...the boat stuff will be fine for repairing your Lotus Elise or Esprit.

More Anon

Rate1

Thank you for the heads up Superworm,

I will dich the stuff I have and find myself the Zap Finishing Resin instead. I can't afford going to big extent trying to reduce the all up weight on this plane to end up blowing it by selecting the wrong stuff building my wings.

CafeenMan

Well, that's typical in this or any activity. What you need to do is actually get to it and learn what works best for you. Some people like to put the resin on thick and sand it off (or not ). I like to build my finishes up rather than waste my supplies and give myself that much more sanding to do.



My experience is that a properly painted model (lots of elbow grease) is insignificantly lighter than Monokote. What I really recommend that you do is build a smaller sport model that is less important to you and glass it as a learning experience. Personally, I would never try a new finish on a model that is very important to me because there is a learning curve to everything and some models I can mess up and say, 'oh well' and other models I just want to be "right."

As far as resin goes, some guys love polyester because it flows on nicely and hardens quickly. Epoxy takes a long time to cure. The downside of polyester is that it is brittle and may show hairline cracks in your finish after a few seasons. It's also REALLY nasty stuff. DON'T get it on your skin or you'll learn how nasty this stuff is. Wear plenty of protection for you hands, skin and eyes.

Best of luck!

- Paul

Rate1

CafeenMan,

That's a good advise. I actually recived the same advise recently after asking my bud, CAPtain232 on RCU and a pro builder.


Well enough of this how to stuff, I know I started it...and thank you all for answering my questions. This is a building thread and we should be talking about issues regarding building this plane.

superworm

Yo Rate1...just as a reminder, Polyester Resin eats polystyrene foam cores...it can find its way in there...perhaps Polyester resin is better for laminating.....

Oh...and one more thing....Epoxy resin tends to leave a waxy finish so after you've done sanding and ready for prime...wipe it down with a Methylated Spirits soaked kitchen roll sheet or two.....you'll also need a "Tack Rack" wipe (from your local paint shop) to eliminate any remaining lint, dust etc before you prime AND topcoat.

OK so i've dug out my bits (!!!) and my digicam so here's a few piccies of my build so far...Fuse first, I'll cover the H-Tail later.

The first piccy show the fuse sides as supplied with a close-up of the sawtooth joint I referred to earlier...the second is a zoom in of same....note the lighning holes which will need Solartex to cover (in my case). Remember, I made 1 piece copies of these from 3/32 liteply.

Then I have a piccy of the Mid-Fuse area to show the lightening holes and the cross-bracing (1/4, 6mm sq balsa) This cross bracing is there because I am going to make the whole turtle deck detachable to get at the internal servos so I need to put the strength back in.

The next shows the cockpit area...painted matt black in advance. You will (maybe later) notice the absence of a fuselage frame in this area. As I said previously, this area will be filled with white painted (as per) simulated tubing (either dowel or "K" metal Ally tubing..most likely the latter or both to simulate the joints...and Patty herself with seat and Joystick. In order to preserve the strength here, I've added a fuse side doubler in liteply with lightening holes where there are none in the actual fuse sides.

The last piccy shows the RHS Aft fuselage cut away (with simulated structural tubing on the opposite side. As you know, there is a Plexiglass access panel over this area of the fuse so that maintenance can see that the elevator horn is properly connected and so that scheduled maintenance can be performed.

The next job, before the fuse bottom stringers are added is to sort out my detachable tail concept...could take a while but we have my Horizontal Tail/Elevator to share with you first.

Cheers for now

Rate1

Superworm,

Nice to see this building thread taking off. I expect my kit to arr soon. When this happens I'll chime in with pics of the build as well.

You meantioned a detachable tail concept...? Do you mean plug-in stab? Do you find this kit easy to build straight? I like your little aft "Plexiglass access panel"...nice touch to a scale plane to include this.

superworm

Yo Rate1

Glad you like the piccies.

It is my intention to have the plexiglass floor panels also but not got that far yet.

I'm not going for plug-on tails. I shall use a bolt-on concept as similar to that I use on the Ultimate and my smaller Extras. The concept involves the Vertical Tail and any associated fairings sitting on and glued to a ply plate which contains a couple of "blind" or "T" nuts (on the Ultimate, this plate is 1/16 ply with 1/8 liteply pads to hold the Blind Nuts). These nuts are spaced about 3" apart fore and aft. The Horizontal Tail has a "keyplate" on its lower surface that keys into a plate mounted on top of the fuselage (we'll call this plate the Tail Seat). This key stops any rotation, fore and aft or sideways movement of the H-tail. Two longish bolts (No. 8 unc on my Ultimate) pass upwards though the fuselage guided by ally (K Metal) tubes that will pass the bolt heads such that the bolts pass through the Tail Seat and such that their heads sit on washers attached to this Tail Seat. (These washers are glued on so they stay put). The bolt shanks then pass through the Tailplane and its attached keyplate up into the base of the Vertical Tail (Fin) and into the aforementioned Blind Nuts. Thus the whole assy is locked and, as they say, it ain't going nowhere. Note that the Fin and H-Tail remain two separate pieces - they are NOT glued together but the H-Tail is essentially "trapped" between the Fin and Fuse. For the Extra, I shall use two bolts side-by side forward as I will need to provide clearance for the (central) elevator push rod. The fin post will be brought down to the bottom of the fuse with another horizontal bolt helping tie the whole empennage to the fuse. When I next get out my Ultimate, I'll take a piccy so you'll know what I'm talking about.

I don't think there is anything difficult about building this kit as per the instructions...the only problem that I can forsee is to ensure that the tail attachments are structurally sound if you are just going to glue them down to the fuse. Methinks something extra (with apologies to SIG) will be required to ensure that the tail mounting piece to fuse side joints are adequately reinforced...needs some sort of overlapping piece to reinforce the butt joint and to ensure that there is adequate glueing surface for the H-Tail to fuse joint...you'll see what I mean when you get your kit.

The hardest part will be separating the Ailerons from the wing after skinning....remember ye olde Engineering adage...MEASURE TWICE - CUT ONCE!

Did you notice that Lanier have reduced the price of this Kit....iirc I paid about $240 (1997)...has to be great value at $150 ish that it is at the moment.


More anon

Rate1

$¤#@£....[:@] So they have lowered the price by $75 since I ordered it and I still haven't recived it... [:'(]

I will have a look at the drawings regarding the tail attachment, when ever my kit arrives, to see if it need any reinforcement.

CafeenMan

Some places will honor a sale price after they sold the item. If they won't then send it back and then order it again.

Rate1

I can't really send it back since there is a massive shipping cost associated with this order... All I can hope for is that they are honest and will refund the difference btw old and new price. Damit... Still eager to get going with the building part.

superworm

....maybe ask Lanier to send you a fibreglass cowling (& maybe the wheel pants) at a vastly ginormous discounted price....

cheers

Rate1

That would be a good idea if I had not already ordered those items together with the kit... I sent them an e-mail requesting a partial refund because of the sales and the fact that I have not recived my order yet. Lets hope they are good people.

superworm

Forgot to mention...

I'm getting my detail for the scale documentation from photos obtained from Bob Banka:

http://www.bobsairdoc.com/

Bob's company is based in California but he has a limey outlet:

https://aeroplanemodel.com/Comersus/...rCraftDoc1.asp

and a Swedish one:


SCALE MODEL RESEARCH
B.K. Model Flying
Bertil Klintbom
Tuer Bro
S-621 73 VISBY
Sweden
46-(0)498-27 27 72



Cheers

Rate1

Latest news about reduced price. It was only a holyday special and only for the lower 48 states. The price for the kit is back up to $225.

I have so far recived some hardware from Central Hobbies, CF wing-tube from Bud Engineering, and a Tru Turn spinner with light backplate. What I am waiting for is the kit from Lanier, hardware from Tower Hobby, some balsa from Lone Star Balsa, and a tail wheel from DP.

Superworm,
Have you seen www.airliners.net for pictures of the Extra? Do a search for Extra and then you get tons of pictures from all angles and different schemes.

superworm

Hi Rate1

Been to "Airliners" before...I used to work at the Lazy "B" in Seattle so have a patriotic interest in all things Boeing.

Never thought of looking for Extra there !!!!

Thanks for the link

More piccies of tails to follow when I've half a mo!

Cheers