gene6029

Im planning on covering my warbird with minwax water based polycrilic & .75 fiberglass cloth. I ran a few test strips today & have a few questions i hope can be answered. First i brushed on a coat of the wb polycrilic & left dry. Then sanded w 220 & applied a second coat, let dry & applied the .75 cloth w the third coat on one piece only. the other piece only had the third coat of poly. After drying they both look the same, i can see the grain thru both the glassed piece as well as the non glassed piece. I plan on sanding these coats, & applying another coat of poly. The plan is to sand that & prime with a sandable primer before painting. Im hopeing the primer coat/ coats fill in any visible grain from the wood. I am considering sealing the wood first with a sanding sealer on another test strip & repeating the above. My main question is this, since the model im planning on applying this to coud have been monokoted, is the glass cloth necessary, or can i just get by with the poly by itself, since im not looking for any strength from the glass cloth. It doesnt appear the glass cloth is hideing the grain as opposed to just the poly by itself. And im not looking for any extra weight. Sorry for the long post but, i know someone out there can advise me which direction to go....Gene

aerowoof

poly is not fuel proof and  if you check the classic pattern forum for a thread called perigee build by wedj you will find most of your answers

gene6029

Thanks im headed there. Im running gas & hope that wont be an issue.....Gene

bps

My Feedback: (3)

Gene,

I have tested a couple different WBP and have found none that I am comfortable with in terms of fuel (gas or glow) resistance. I have used water based products to apply and seal my Sig Koverall. Also plan on painting with latex and then sealing with War Bird Colors water based clear coat. Just have to make sure the process you use is compatable. No need to worry about the sealer and paint with most latex, just overcoat with something like the WBC clearcoat.

Also when you apply the initial coats to the balsa you are just sealing the balsa, not filling it. No need to fill the grain as you will be applying a covering and its job is to add strength and smooth the surface a little. Once the covering is applied you can begin to add filler coats and then a sandable primer to get the surface ready to fill any lowspots and then paint. So seeing the grain is normal and even seeing more of the grain after the initial sealing coat is to be expected.

Best luck, let us know how it is going for you.

Gray Beard

My Feedback: (-1)

Ihave used the poly-u and sanding laquer for glassing and love the finished product. Iuse two coats of sanding sealer first then sand then glass using the poly, I sand that after the second coat. Then I mix my poly about 50/50 with baby powder then do two or three coats with this mix sanding between coats. The baby powder is sanded off except from the pores in the glass so the plane comes out nice and light. Ionly use the 1/2 oz glass too, that seems to work better for me then the heavy .75 oz.

Gringo Flyer

My Feedback: (18)

You do need the glass.  The wb poly will fill some of the grain and weave of the glass.  For th latter coats of WB poly I generally add some microballons.  However, your primer is what will fill the weave.  Use a high build auto primer.

campy has a good article on how to use the wb poly if you just do a search for it here on RCU.  http://www.tompierce.net/190/index.htm this is also a good place to see how its done. 

gene6029

Thanks guys, my head is spinning with all this info! I have been reading about this process for the last few days and so far i like what im hearing and what ive done so far. Cant thank all of you enough! .......Gene

Jim_Purcha

My Feedback: (8)

I've started a WBPU finishing job on a plane presently. I have most of the plane covered with .75 oz. cloth and minwax. Did some initial priming, Dupli-color Primer  (FP101). Some of the weave of the cloth is showing through, so I have sanded back the primer and going to add a layer of baby powder and minwax to the plane. If it warms up again.  This is my first attempt to paint a plane in several years. Planning on using latex paint.

Jim

gene6029

 I want to order some glass cloth online. Any one know a place that has it in stock? I dont have enough to finish my plane right now and dont want to be looking for it once i get started. Im going to try the powder on a test sheet, thanks...Gene

Jim_Purcha

My Feedback: (8)

Check with Sig Mfg. [link=http://www.sigmfg.com/cgi-bin/dpsmart.exe/MainMenuFV4.html?E+Sig]Fibreglass cloth[/link]

Jim

42etus

My Feedback: (2)

Here ya go.
http://www.tapplastics.com/
Click on Fiberglass Fabrics on the left margin.
Paul

gene6029

    thanks for the help so far. One more question. I have to cover over open wing bays. I have been thinking of either Sig Koverall, trimmed just past the open bays, then poly over the entire wing. OR been thinking of silk over the entire wing. I cant find anything after searching if the silk can be applied with the polycrilic, in the same way you apply it with dope. Any ideas or places to point me in? The wing is a D tube wing with open bays. The model is a Chipmunk, and i want the leading edge to simulate a metal (smooth) finish but have the fabric effect over the open bays.....Gene

andrew66

http://www.rcuniverse.com/forum/m_8088219/tm.htm  this is the thread i did on it. 

gene6029

Andrew66, great information there, thanks alot , this is a big help.....Gene

dasintex

My Feedback: (10)

Gray Beard;

In your reply on Post#5, you said you use 2 coats of Sanding Sealer prior to the WBPU; did you sand between Coats, what brand of Sanding Sealer did you use, how much time between Sanding Sealer Coats;

I plan on going this route on a RTC Top Flite Giant P-51 ARF; I will be using Deft Sanding Sealer and Minn-Wax WBPU and 0.50 oz glass.

Thnaks, Doug

Gringo Flyer

My Feedback: (18)

You can get by with just one coat of sanding sealer.  It's just to prevent the balsa from soaking up a bunch of the water in the poly and warping.  You can actually apply a super thin coat of poly in place of the sanding sealer but the sealer is better.

dhal22

i do a coat of sanding sealer 1st, then i add a coat of watered down hobbylite balsa filler before i sand.  an easy way to get started on filling in the wood grain that will show as well as the glass weave that you will deal with later.  i then glass and paint with wbpu at least 3 times before sanding.  i then switch to wbpu mixed with talcum like everyone else. 

the cheapest way to prime is to buy from an automotive paint store.  i buy from sherwin williams and just roll it on.  lots and lots of sanding but wow what a smooth finish.  my biggest problem is i now have 3 planes and counting that need to be painted.