jroth

My Feedback: (60)

Thanks for the West Systems info, I just purchased a 100g by .01 gram scale for $22.25 on Ebay.
[link=http://www.ebay.com/itm/160714219674?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649]EBay[/link]

RCdude13

My Feedback: (6)

I'm going to try something totally different...lay some 3/4 ounce cloth on the sheeting, then start dropping on thin CA. I'll use an air compressor to blast around the CA. The CA will bind the fiberglass to the balsa and hopefully form a hard shell. I bought a few 2 oz bottles of thin CA from Hobby King. What do you think of this idea?

Warbirdguy

I have already done it. Here is what I learned. First spray a lite coat of spray adhesive to the wood only. The you can stretch out the cloth to get it smooth. The starting at one end, just start putting it on. A few drops at a time. It will wick out and not leave any puddled. I put the wing at an angle and started at top and let it run down, adding some when it stops flowing. Only thing I can say is, dont use accelerator, it will blister up. and do it in a well ventilated area. Or you gonna think you just peeled a room full of onions LOL. Other than that, it worked great. Just a little too expensive for me. I did this on a BVM Maverick years ago.


WBG

saramos

I think that there would be a few problems with this method. One would be the potential of not getting a smooth bond between the glass and the skin, leaving bubbles under the glass and lifting around the edges. The second is that it would be very rough, requiring more filling causing a heavier result. Also the fast cure time would leave you with almost no time to make any adjustments.

Scott

jroth

My Feedback: (60)

Hi,

The old rule as stated above is that it was too expensive, if HK is selling it cheaper that finishing resin, it may be an option.

I have used thin CA on small flat surfaces like servo hatches.

I lay the cloth on the wood, drop some CA on the cloth and spread it our with a plastic bag over my finger. The CA will not stick to the "ziplock" and you will be able to smooth out the cloth. Then you and sand and fill and sand to create a primable surface. I do not know how it would work on compound curves.

Good Luck, let us know your results.

John

Warbirdguy

Nope Scott, if you use a light coat of spray adhesive. It will hold the cloth to the wood. It wicks perfectly into the weave. If you use accelerator, it will blister up and then you have alot of sanding to do. Like I just said in previous post, I can speak from experience, It does work. The trick is the spray adhesive. Just LIGHTLY on the wood side. The cloth will lay on it and you can pull edges to get rid of any wrinkles and raised areas. smooth it out with your hand. Give it a try on some scrap. You will see what Im saying. Took me a few attempts to get it right but the method does work. Just, with the price of CA's now, its a real expensive way of doing it. The plus side is, in a couple mins, your ready to start sanding and painting If time is an issue, this is the way to go if you have the extra cash to do it this way.

WBG

RCdude13

My Feedback: (6)

Glad to hear that the CA method has been done. I was planning on getting someone to stretch the fiberglass over the part and hold it in place while I drip the CA. I have used spray adhesive to attach the fiberglass when reinforcing the inside of a cowl. If you apply too much adhesive the CA does not bind to the surface below. I bought four bottles of 2oz CA from Hobby King so I hope I have enough.

Warbirdguy

Yup, why I used the term ...Lightly.... just one quick pass is all that is needed. Let it dry to the touch. Then put the cloth down. Just smooth it out with your fingers. The CA will wick into the weave and into the wood. Makes it harder than a preachers....well....you get the point LOL.

WBG

nwadc10

I followed the link and was going to order the scale you referenced. Then Isaw it's maximum capacity was 0.22 lbs which seems almost unusable for any other task or for larger batches I would assume.The price on that scale is very reasonable but I am willing to pay more for a scale that can be used across a wider range of tasks. What are your thoughts on this scale?
http://www.gramscales.com/product_in...oducts_id=2344
or this one:
http://www.gramscales.com/product_in...roducts_id=338

Both have a resolution of 0.1g, will that suffice or is it imparative to have the 0.01g resolution?

nwadc10

Ok guys, I made it to the hobby shop and a few other places today. I picked up a small pack of .75 oz fiberglass cloth, Z-Poxy, light and dark color primer, a couple test cans of paint one of which is Top Flight's Insignia Blue (in case Idecide to paint it like the box...which Ireally like but would match it up with a proper aircraft number and some details to those colors) and I think it was a Tamiya ?sp? random color. Additionally Igot some long plank of balsa, preformed leading edge balsa piece and also a preformed aileron balsa piece. With the balsa Iwill form a couple of mock airfoils to test applying the glass on the curves of the wing and wingtips. I also got Bondo and the equipment to go with it as well as microballoons. As you can see Iwill test a couple of the methods pointed out here and see what happens!

Finally, leaving the hobby shop Ifound that Ihad accidentally bought the F4U Corsair kit! I don't know how that happened. LOL A little bit of what this model means to me, when Iwas a teenager and first entered the hobby Iremember seeing this model in the Tower Hobbies catalogue and fell in love with it. I love the gull-wing look. I used to dream about this model LOL. I left the hobby before college because I didn't have room and wasn't near a flying field and just plain didn't have time. College was over years ago but still didn't have the room to be working on models and still was too far away from a flying field. A couple years ago I was finally able to get back into the hobby. I talked to some guys Iwork with and I was recommended for my first kit build (previously Ihad only done ARF's and trainers at that) a Sig Four-Star 40. That was a fun build and that airplane and Iare good buddies, great flying airplane and I pass on the recommendationfor it being a good first time kit build. Next Igot the Ultra Sport 60, again on a recommendation (same guy actually). I just got that built last year and Iput in retractable landing gear, tail dragger configuration. I have only one flight on that before it was the end of the flying season. This was also my first 60 size airplane. All of this was in preparation for this F4U Corsair build. First to practice just kit building, then installing landing gear. The Corsair Iintend to do the retractable landing gear (I waiting to see the details on the new Robart electric gear), flaps, some scale mods from this post: http://www.rcuniverse.com/forum/m_96.../tm.htm#964845(sorry for the anchor in the link, that's where Iwas when Ibookmarked it I guess)

Finally, of course, fiberglassing.

I appreciate all the help everyone is offering, I'm listening to everything you guys have to say!

Mk23socom

My Feedback: (7)

Good luck Justin! I remember when i started my P-47, I couldn't hardly contain myself I was so excited! Now it's in the books and I have moved on to a bigger version of the same thing! The information that I lent and all the rest that the other fellas contributed will help you a ton! t if you are going to use something under the glass to help smooth out the wood, I recommend lightweight spackle. The Lustrecote, you will find, is easy to use and if you are powering with glow, don't forget to clear coat it. Kick it off buddy!

jroth

My Feedback: (60)

Hi Justin,

For my use, the 100 gram scale by .01 grams should work, I did see other scales but they were not as precise. I will probably only use this scale to weigh epoxy and I am afraid that eventually it may become covered in glue. I liked the $22.25 delivered price.

The scale that I bought weighs up to 100 grams or approximately 4 fluid ounces.

When glassing with West Sytems 105/205 I use one full pump of each and that is about 2 fluid ounces. I have to work fast before it starts to kick over and the exothermic reaction takes place. I would recommend that if you are working by yourself, not to mix too much epoxy, even the finishing resin can start to react in minutes if it is in a large mass.

I was glassing today, I mixed up 4 batches of West Systems, I glassed the top of the fuselage, the top of the horizontal stab and the top of the elevators and ailerons on my 1/4 scale 114 inch wing span F9F-2 Panther jet. I can not see a much larger model project or needing to mix larger batches to do fiberglass work.

If you have other plans for the scale or will be mixing larger batches of resin, then you may need a larger scale.

Good Luck

John

dreadnaut

My Feedback: (5)

I concur on using a scale. When I started using West System I got the pumps. They work well, but on a lot of little jobs I wound up wasting a lot. The scales let me get a precise mix ratio at much smaller volumes than the pumps deliver.

Warbirdguy

I agree about the scales also. For smaller amounts, its wise to weigh it out to conserve material.

TIP: When mixing up a larger amount of resin, like two pumps, after mixing in a cup, pour the mixture ito a pie pan. This will keep the mixtures temp lower so it doesnt go off as quick. Gives you way more working time I learned this after my first attempt of laying up some glass parts in my first mold eons ago. Using slow hardner, I thought I had all the time I needed, wrong. LOL. When its in a cup, the reaction creates its own heat. The heat speeds up the curing rate. My first cup of 4 oz of resin, came close to igniting after about 10 mins [:@] I threw it out in the yard cause it was smoking so much. An other mold builder laughed when I told him what happened and he gave me the tip about pouring it out in a pie pan. (make sure its not the kind that has pin holes in it lol) Never did I ever have resin going off with me after that.

I also keep a coffee can full of acetone nearby. Just drop your paint brush in it after your done and you can resuse it several times. Use the cheap ones with wooden handles and hair bristles. Nylon bristles catch the fiber in the cloth and pull them.

You may not even use brushes, but for large projects, you can put alot of resin down and do the initial spread with them.

That and a $1.00 might get you a cup of coffee somewhere

WBG

nwadc10

Light weight spackle, thanks. I meant to get that too but with so many things to put on the list I failed to put it on there. On the list now. Since we are talking about the balsa level of the project, what is the sand paper recommendation for the most refined sanding? I'll admit that when using Monokote I am rather lazy at detailed sanding and I would do a light sanding at 120 and another light (by light I mean quick LOL) sanding at 220 and call it good.

nwadc10

You bring up a good point and I guess a statement Ihad implied without thinking about it and will make explicit here.I have no frame of reference as to how much epoxy I need to mix up to do a section. I think I understand what I need to get the section to look like as far as proper epoxy coverage goes but in terms of how much epoxy that actually is, that's what I don't know hence why I am unsure about the 100g limit of the scale. 100g seems to be almost nothing for weight and my normal 30 or 5 minute epoxy even in a small batch feels like it isn't exactly light. I will be working alone and mixing enough epoxy for one section at a time makes absolute sense and also explains why the 100g scale must work.Ipictured in my head mixing a relatively large amount of epoxy to do the job all at once...this being a result of complete inexperience.

On another note, I happened to notice in yourthird photo what appears to be a handy epoxy holder, centered right between the parallel 2x4's. I recently did adjustments to my US60 (dumb directions didn't specify the coil on the landing gear had to face rearward, not forward LOL) so I mixed some epoxy somewhere in the process. I'm sure many of you have been near the end of the bottle and have had to wait a few minutes for the epoxy to slowly creep its way down to the bottom so it can be used. I wondered if there was such a product as what Isee in your photo. Did you make that yourself?

jroth

My Feedback: (60)

Hi Justin,

Yes, I made the glue stand out of 1/4" cleap plywood, I think it was a group project, all of my builder friends have them. You only need it for 5 minute and 30 minute, the finishing resin is very thin and can be stored upright. I never used 15 minute epoxy.

I am glad we can help you learn about glassing.

I only use light filler under the glass cloth, you should be able to see the white filler under the glass.

John

saramos

As for amounts, 2 oz batches work well for me. If you need more, it's quick and easy to mix another batch. Use a fresh cup to mix in. If you try and reuse the old cup and stir stick, the older epoxy can shorten your work time and make the epoxy a little gummy when applying which can pull to much on the glass. As mentioned earlier, the more spread out the epoxy is, the longer the working time, so try and get the epoxy spread out relatively quickly, but don't race to get it done. Once it's on the plane, you will have plenty of time to work it. I like to use the fake credit cards that you get in the mail to spread it.
Once down, with some paper towels handy, I squeegie off the excess. I also like to use a roll of toilet paper to get more off. I roll the toilet paper over the surface in the direction so the paper won't unroll. Once I go a full revolution, I rip off the used sheets and keep going. I like to do this until the surface looses it's high gloss. The result is an even textured light application of glass ready for filling the weave.
Here's a photo of the result after filling the weave, ready for priming and detailing.



Scott

wyowindworks

BTW, a 100 gram batch of laminating epoxy is just short of 3 fluid ounces.

100 grams / 1.18 g/cc (specific gravity of mixed resin) = 84.75 cc of resin
84.75cc x .0338 = 2.86 fluid oz.

I rarely ever work with a larger batch than 2 oz when building models. Trying to work with one batch is just asking for trouble on larger project. On a 40" discus launch glider fuse that I produce, I use a 4 gram batch and three 6 gram batches.

Warbirdguy

Scott,

I like that about the toilet paper. Now, if I can just figure out how to get whats left on the roll back into the bathroom without the wife catching me.....Id have it made

WBG

Iron Dog

OOPS!!! Didn't realize that this thread was 3 pages in when I started, so my comments (above and below) were in response to the information presented up to the end of the first page. Probably a bit too late at this point, so feel free to disregard; and my apologies to all.)

Best of luck with the new plane. If you are interested, many of the different techniques I discuss above (and more) are demonstrated on my build link;

http://www.rcuniverse.com/forum/m_9659845/tm.htm

I started this thread to serve as an introduction for some of my friends to my fiberglass construction methods, as they had many questions, too. I need to make it clear that it does NOT discuss covering a plane (as a replacement for film and fabric coverings); but, it does rather thoroughly cover the different formulations you've been asking about, tools, mixing techniques, beginner mistakes to avoid and other lessons I've learned the hard way, fillers, cutting cloth, etc. You might find it helpful as you continue to expand your skills in this particular facet of the hobby.

Warbirdguy

LOL Iron dog, at least you caught it early. Ive posted to a thread once that was over 4 years old LMAO. I just saw something on the first page and responded to it. There were like 35 pages total. I felt like an idiot [:-]

All comments, repeated or not, are welcome. Its an open forum. There is always something to learn in all those words if you read through them.

I have learned that if you can sneak a roll of toilet paper out the house, you can use it to soak up extra resin. Just make sure you get the wet paper completely off before you sneak it back in. Or the wife will have your a**

WBG

Iron Dog

jroth

My Feedback: (60)

here are photos of the epoxy stand:

Warbirdguy

Ill have to build one of those Ive been using an old quart sized yogurt cup.

WBG