Glassing
 

Ok guys, I need some help with my memory here. It's been about 7 years since I built and glassed plane.
Im getting close to the finishing stages of my TF P39 and I want to glass it.

I for the life of me cannot remember all the steps I took when glassing. If memory serves me right, I laid the 3/4 cloth on the parts, then mixed denatured alcohol with a little bit of epoxy and blushed it all on.
Does this sound right?

After it dried I think I mixed up some finishing epoxy and spread it all over the surface and removed the pooled areas to make it all smooth.

Am I forgetting anything?
I can't remember if I mixed the alcohol with the finishing epoxy on the final application or if it was epoxy alone.

Also, I can't remember where I got the denatured alcohol, I think someone just gave me some, where can I buy it?

Glassing
 

Well welcome back Shok. This subject has been discuss here many times do a search on it. Here is a link that shows everything in details. If you have any specific question shoot me a PM.

http://www.arts-hobby.com/fiberglassing.htm

Glassing
 

I have an little guide on how I do glassing on my web site. I don't have pictures yet but will soon.

glassing
 

Hi Shok you can check out my site here http://home.mchsi.com/~jahuntley/help.html look for the linkg glassing with Poly U. theres a big flow going to Poly U over epoxy these days as it is much easier and lighter weight not to mention a whole lot easier on your wallet.

Joe

Re: glassing
 

Joe, you use Deft clear wood finish correct?
Thats it?
Your write up was very interesting, I think im going to try this.

One thing im curious of.
The contruction of the control surfaces on this plane do not lend themselves well to covering of any sort.
Im wondering if I can just put about 5 or 6 coats directly on the wood, wet sand then primer....will it give a good result?

control surfaces
 

Hi Shok I was recently asked something like this on my rcwarbirds advisor column. The problem with just adding to the wood is that you leave the wood vulnerable. just like moneycoat adds strength to the wood it covers so does a layer of glass. for instance a sheeted wing. if you add moneycoat it adds strength as it helps it hold together a littl better in a crash or even helps to make it harder to punch a hole in the sheeting. by adding a layer of glass cloth when you glass this will add the same kind of strength. if it is just a control surface remember there are open bays under the wood so still a chance to be damaged. if you put a layer of .5 oz cloth down when you put your few layers of Poly U on the controls you wont be adding any thickness to worry about any more than you would add putting you several layers of poly on. remember poly is paper thin when going on as it is as thin as water to apply already and not like epoxy which has a lot higher viscosity (right word?) so I would go that5 way but if you want to just use the poly U it will work to give you a paintable surface but remember it will be weak and prone to breakage.

Joe

Glassing
 

Yeah i may have to just coat them in epoxy.
The deal with the control surfaces on this kit is that they are ribbed sloping to the trailing edge.
Getting fiberglass cloth to conform to this would be very difficult.

surfaces
 

well if they are not sheeted use solartex it is a good fabric covering and very strong. you can get it i believe through balsa usa. it is pre-primered and ready to paint and you just iron it on no need for epoxy or anything else over them.

Joe

Glassing
 

Will the laquer based Poly U soak through contest balsa and attack styrofoam underneath?

Poly U
 

I do not know it depends on the sheeting. I am sure 1/16th it may soak through but on thicker might not. If I was using sheeted foam I would prob use the water based poly U. when using water based on open framework with thin sheeting it can cause slight warpage sometimes but if your sheeting is stuck down to a foam core I dont see a problem as the core will keep it from warping. if I was using the laquer based I would use a couple coats of sanding sealer as that will keep the poly from soaking all the way through the wood.

Joe

Glassing
 

So the only reason you prefer laquer based vs. water based is wood warpage?

Specifically, I'm looking to possibly glass my next pattern plane. The wings and tail feathers are 1/16" contest bonded to styrofoam with polyurethane glue. I agree with you that this would not warp.

The fuselage is 1/8" contest balsa with formers every 12 or so inches.

I guess I could use water base on the sheeted foam and laquer based on the rest. Is there any difference once the water or laquer dries? I read on your website that the laquer leaves a gummy residue. How big a hassle is it to remove this residue?

Do you foresee any problems using 2-part automotive primer over the Poly U?

laquer vs water
 

The last question first yes the 2 part paint works fine over it.

As for water vs laquer one thing you must know abt me is I used to paint cars and my plane and when i did taxidermy my fish and stuff all with laquers I love laquer paints because of their blending ability so it naturally went over to the poly U.

But realistically I like the laquer based poly U because to me it gives a harder surface and finish. I had a run once and couldnt cut it with 60 or 80 grit sandpaper but when I used 320 wet/dry paper and wet sanded it i found it cut nicely (go figure). with the water i felt it didnt give quite as hard of a finish but still a nice finish. if you were to give your wing 2 or 3 coats of sanding sealer sanding between each coat I dont see a problem using the laquer based there but I would suggest trying it on scrap. Water based seems to take longer to dry is why I dont like it and of course it is burnt into my head water and wood dont mix. There are people who have noticed warpage or raising of the sheeting in places using the water based and otheres who have used sanding sealer or 1 layer of epoxy first to protect the wood then using the water to finish without problems. I dont use foam at all so have never tried it but I would bet a bundle that if your seams were filled and you used sanding sealer you wouldnt have a problem. I think I would just paint some laquer based directly on some foam and see what happens maybe it wont even affect it thus we are needlessly worrying. I have some 2 " beaded foam downstairs I think I will try it on this afternoon and post the results.

Joe

PS
 

As for the gummy on top of laquer based you will not feel it being gummy it will wet sand off easily it just gums up sandpaper til you get that microthin layer off. what that does is to help make the finish rock hard and draws all stickiness out of it. Fiberglass and gelcoats do the same thing. I was plant manager for a while at a fiberglass boat factory and we went through a lot of sandpaper to cut that layer what it basically is is wax that is mixed in with the resin and paints to seal it off as it hardens which gives it a nice hard finish.

Joe

test complete
 

Ok I put some on some 2 " beaded foam and it really attacked it so if it hits the foam it will damage it BUT here is something that just hit me.

When you sheet foam cores you put a thin layer of glue completely over your core then lay the sheet down. What you are doing there is creating a barrier of glue between your foam and the sheeting thus protecting the foam from liquids touching it. So my suggestion would be to add 2 layers of sanding sealer then you will not have a problem with the laquer based for the wing. I would still test this theory but if you think about it the glue, if any thing soaked completely through the wood, would stop anything from attacking your foam core.

Joe

Glassing
 

Yes, I use Polyurethane glue to sheet my wings, and yes, there is a thin layer of glue between the sheeting and foam. However, what I don't know is how uniform that thin coating is and the laquer could form voids. I guess that the only problem will be with the first coat??

coat
 

yes the first coat is the only problem something to seal off the wood. thats why i suggested 2 coats of sanding sealer that will seal the wood and that suffs cheap

Joe

Glassing
 

ProfLooney,
I couldn't find laquer based poly, but the local home depot had "MinWax Fast Drying Poly". It's oil based, and cleans up with thinner or mineral spirits. Is this the same thing? They didn't have Deft products. Is there really a big difference?
Thanks,
--Rick

Poly
 

Rick i really dont think it makes a big difference. the main problem I have with the Minwax is like you said it is OIL based. then I think about the paint going on top of it and whether it will stick or not. I have heard of guys useing it and says went on great I just have not heard of the after reports of how well the paint adhered and if it did how long it lasted.

Joe

PS on my tips page http://home.mchsi.com/~jahuntley/help/help.html#Tip 8 there is a huge list of places to buy it. maybe you have one of them stores by you that may have it or you can try the oil based and let us all know how it turns out. Poly is Poly it is just the base that matters

Glassing
 

ok, this might be a stupid question. How much weight does glassing a wing add to your plane? Can you Monokote over a glassed wing? Thanks!b

weight
 

There was a guy done tests on glassing vs monocoating on one of the threads here using .5 oz glass and i believe the glassing only weighed a few grams more than monocoating using laquer based poly U. so basically they both wegh the same. I dont monocoat but most people say that you can monocoat over a glassed surface and it sticks a lot better than over porus wood.

Joe

Glassing
 

Monokote sticks very well to glass/epoxy--better than to bare wood. Also sticks to water base polyurethane just as well. Plastic to plastic, I'm no expert but my experience is they all stick well to each other.

Glassing
 

Yes, the oil based poly works fine, but I switched back to the epoxy. It took a really long time to build up the thickness with the poly, and was not sufficiently hard/stiff for my application. For glassing a wing or fuse, this would be the way to go though.

I found the poly: The water based could be done on the kitchen table over a few newspapers, fast drying, less messy than any other process I've tried, easy to do, and I must mention easy to do. Using ProfLooney's site: http://home.mchsi.com/~jahuntley/help.html , you can get a great finish in no time. Although, the site is down at the time of this posting.

My SIte
 

OK Guys I redid my site and organized sections into folders. Thus if you have any links other than my main page you might want to go through my main page and resave the page you want. Here is the new link to my help page. Notice the help folder added to the url

http://home.mchsi.com/~jahuntley/help/help.html

Joe

Glassing
 

Joe, you are a good man. I'll look you up and buy you a beer next time I'm in Moline.

thats a date
 

HAHA thats a date just dont let my wife know she'll get jelous cause i wont go out with her rofl

Joe