flysalvo

I am in the process of fiberglassing my Top Flite Hawker Sea Fury with 1/2 oz. cloth and Z-poxy epoxy finishing resin. I was tutored on fiberglassing techniques by the folks at Century Jet models, and so far have had great success on my airplane. I am considering filling the weave with (lightweight spackle) but am not familiar with what type of spackle how exactly to apply it (thinning required) and where to purchase it. Thank you for any input.

Mel Francis

Here's the filler that the 1:1 composite aircraft builders use. It's lighter than any other filler I've
used, and sands really easily, so you won't cut into your cloth laminations.

http://www.aircraftspruce.com/catalo...opoxylight.php

TrueScale

My Feedback: (47)

For 1/2 oz cloth it shouldn't take much to fill the weave. Just use a good
sandable primer thats compatable with your paint system. just make
sure it is dry before sanding.

Chuck

Irish R.Seer

My Feedback: (1)

I have used Minwax Polycrylic water based filler, available from the local hardware store. About 3 or 4 coats of this stuff will fill 1/2 oz cloth ready for priming, and it is lightweight.

flysalvo

thank you for the tips. The aeropoxy light seems foolproof, but the minwax method sound interesting as well. I have filled the tail feathers weave in with just spray on sandable car primer and it has taken no less than 6 coats of the stuff to achieve the results I want. I will have to buy at least 10 more cans of the stuff to finish the airplane at that rate. I have heard of some people using lightweight wall spackle for such applications. I wonder how their results have been.

Leo

I covered my balsa sheeted 1/4-scale Curtiss bipe with 3,8 sq.yards of 0,6 oz. cloth and epoxy.
The weight gain after the first coat was 8,1 oz. (incl. 2,3 oz. of cloth)
A second coat of epoxy, applied with a plastic card, was enough to fill the weave and added
only 1,8 oz of weight (or 0,5 oz/sq.yard)
/Leo

TrueScale

My Feedback: (47)

Yikes, 10 or 12 cans of primer just to fill the weave on a 60 size plane with
1/2 oz cloth is way to much.There are many different types. But if your buying
the cheap lacquer it doesn't fill or sand that well for thicker filling. You would
want a high build primer. Or use the aeropoxy light as it good stuff as Mel
suggests.

davidfee

Lightweight spackle can be used quite well. Get a broad plastic spatula from the paint department while you're at the home center getting the spackle. Use the spatula to squeeze the spackle into the low spots in the weave. You can scrape most of it away before it dries. When fully dry, sand and spray sandable primer. Then sand again, etc. As was noted, get a good high-build primer. A lot of the stuff out there these days just isn't very good.

good luck,
David

flysalvo

Thank you gentlemen, I sincerely appreciate the advice. I have decided to try the light weight wall spackle from HD, test it out while waiting for my aeropoxy to ship out.

boater

My Feedback: (2)

Spraying on a lite weight primer would probably save you a lot of sanding. Can't imagine sanding down all the overlaping marks from slathering on those pastes. Too bad they don't still make the Superpoxy primer by K&B, it was very light , easily sandable and helped show problem areas, haven't tried Ultrapoxy yet, still working on my Superpoxy stash. Also look at Klasskote.com, they say they have compatible stuff, but priced lower than currrent Ultrapoxy prices. Only comes in quarts, though.

Patriot

They specifically make primer filler in spray cans for this kind of thing. I is thicker and easier to sand than regular primer. It is the layer they put on the metal before regular primer is used for automobiles.
Lightweight spackle also works well. If you add water to it, it will thin out and actually collapse, and become brushable. You can brush on a thin coat and it will dry in only a couple hours, ready to gently sand perfectly smooth.

Patriot

Larry S

My Feedback: (6)

Hi Guys, very interesting subject. I have tried several different combinations of filler and found Krylon primer/sealer to work good. You can get it at Wal Mart and is fairly cheap. I'm glassing a TF FW190 and using West System epoxy and Krylon and getting a nice surface. I do have a question to all here, why would you want to put spackle over a glass surface? I do use spackle to fill dents and make fillets but only before putting resin on. I'v found that spackle has to be sealed or you run into all kinds of problems. So if you first glass the surface, then add spackle and glass again to seal it, you've added quite a bit of weight. If you don't seal the spackle, it can dent or break off because it is fairly soft. I might be wrong, but I would rather have a hard surface to paint on then painting over spackle. Besides, that spackle will absorb the paint like a sponge, again you added weight. I just think using a product made especially for filling a weave is better then using spackle for that purpose. What do you guys think?
Larry

I did edit this post earlier this morning giving credit to Chuck for his help and stated I would try the filler Mel suggested. Well, I changed my mind, not about Chuck but about using something different then Krylon primer/sealer. Reason, I just sanded down the glass on my wing and was ready to use my filler. Well, on the can it saids it will be dry in 4 hours. Fine, I spread as thin a coat as I could without missing any areas, watch 10 minutes of basketball and the Krylon looked dry. So I took some 440 paper and guess what, I ended up with a surface as smooth as a cat's ashtray without any weave showing at all. I'm sure the stuff Mel suggested is good, but for the money I'll stick with Krylon.

TrueScale

My Feedback: (47)

Thanks Larry

I have never used it either. I use auto primer or depending on the weave thickness Acrylic glazing putty.
I tend to stay with the acrylics as some paints won't cure properly or the clear will leave small drop like
marks where the clear runs away from it (like oil and water) Either of these methods work well with little
weight gain. I'm sure there are a ton of types.

Chuck

Larry S

My Feedback: (6)

I said I stay with Krylon primer/sealer but I still had a few spots where the weave showed throught so I tried Patriot's idea and that worked great. Only thing, spackle is a water base product so you can't wipe the plane down with a damp cloth without possibly wiping off the spackle. I guess my next step is to spary my primer to seal the spackle and give me a good base coat and sand that down very lightly then start painting. My problem was whenever I used spackle I would use a very thin coat of epoxy to seal and harden it. Is this the way to go or can I just spray my primer and hope that does the trick?
Larry

flysalvo

Larry S, Just thought I would update this post with my progress with my Sea Fury and the weave filling and sanding. The cheap auto primer I was buying had no building properties to it, the light weight spackle was a lot of work (applying and sanding, applying and sanding), so I went to the local auto parts store that just so happens to specialize in auto paints and bondo and fiberglassing equipment. They had a high build primer that I thought I would give a try, problem is, it is 15.00 bucks a can. I dont know about you fellas, but I spray, sand, spray, sand and then do it all over again, I like to have my scale panel lines embossed in my primer. Good primer, but expensive. I decided to give the Krylon primer/sealer at Wal Mart a shot. Less than 3.00 bucks a can. The filling and building qualities of this primer are so superior to all the other methods I have tried I can't imagine "not" using it again on my next model. It sands beautifully as well! Thanks again for the tip Larry. I hope that this thread helps another fledgling builder as much as it has helped me. Oh, and by the way, fiberglassing a sheeted model is so totally worth the time and effort. It isn't as difficult as one would be convinced of by other builders. If done properly, the added weight to the aircraft is minimal, but the appearance, well, it can't even be compared to film coverings.

buttuh

If you guys get a chance try Duratect high build primer. It's polyester based and can be sprayed on as many layers as you want in one sitting. Just let each coat flash off for about 2 mins and you're good for another coat. I normally mix enough to spray about 5 coats at a time and then mix more if I need it. It'll cure to sand in about 15 mins if you put it under high heat. Otherwise it's cure to sand in about 4-5 hours.

Larry S

My Feedback: (6)

Flysalvo, sure glad it worked for you, I know I have had good results with the Krylon primer/sealer. Even though it filled great I still had some small areas where I needed to fill so I tried another method I learned from a man on one of the forums. I had a small amount of spackle left in one tub so I added water to the point where I had a brushable paste. I then brushed a coat of that over the Krylon and sanded it down with 220 paper. I ended up with a glass smooth surface with no weave or pin holes. The only thing I'm not crazy about is spackle is water base so don't wipe the plane down with a damp cloth or the spackle with wipe off. What I did was after I used the thinned spackle and sanded, I use Krylon spray primer to seal the surface. That combination worked the best for me. Both the Krylon and thinned spackle are very easy to sand down. So what I'm saying is, even though the Krylon primer/sealer is great and easy to use, you still need to do one more step to get that perfect finish. I suppose you could put a second coat of Krylon primer/sealer on your plane and get the same results but I'm still from the old school where I like to use a sprayable primer before applying my top coat. So here goes, first coat Krylon primer/sealer over areas you fiberglassed and sand with 150 grit paper. Second coat with thinned spackle over all areas where you fiberglassed, sand with 220 grit paper. Third coat with Krylon sprayable primer over entire plane, cowls, plastic parts, everything. Sand with 440 grit paper and you're ready for your top coat.
Larry

JeffH

My Feedback: (43)

I use either Nasson or Dupont fill'n'sand laquer auto primer. I brush it on unthinned, or thineed just a touch to make it brushable. I brush it on heavy to fill the weave. Sand it all off and do once more, then spray a coat to find defects, fix them, then spray a VERY light coat, just enough to give a uniform color.

Bruce Thompson

I agree with Buttah! I use Duratech almost exclusively now. They have two versions that I use. One is the "Regular" that is VERY high build and can be polished to a "plug" quality shine and also a version called Easy Sand. The easy sand sands like laquer based primer but builds very fast. You can thin it with medium laquer thinner and spray it very lightly (ie 1/2oz glass) It is actually cheaper then laquer primer from NAPA. You can purchase it at Applied Vehicle Technologies TX# 317 546-6840. They also have a clear version.