Charlie Kellogg's TBM Avenger Build
12-07-2013, 09:06 PM
#1826
That spot putty is not the best thing to use here. It will shrink and crack over time. Evercoat Metal Glaze is a much better product. It is a catalyzed putty. Is dry and ready to sand in 15 min. You also might want to wait and do the filling after you glass the wing. You will find you will have a low spot all around the edge of the filler as you will sand the soft balsa away. Don
12-08-2013, 10:11 AM
#1828
Chic,
Don is right on, we did spot spotty after we glassed and have hand no problems with cracking with the spot putty. We did of course have the problem with air pockets under the glass after the wings were out in the sun for an hour. When you glass make sure you get the resin through the cloth to adhere to the balsa. We think we had some spots that the resin didn't get through the glass and that's why we have a few small bubbles in the upper wing surfaces...
Larry
Don is right on, we did spot spotty after we glassed and have hand no problems with cracking with the spot putty. We did of course have the problem with air pockets under the glass after the wings were out in the sun for an hour. When you glass make sure you get the resin through the cloth to adhere to the balsa. We think we had some spots that the resin didn't get through the glass and that's why we have a few small bubbles in the upper wing surfaces...
Larry
12-08-2013, 02:00 PM
#1829
That's why you use "peel ply" when you glass anything. It is a layer of dacron aircraft fabric like Stitts or Ceconite that you squeegee over the wet fiberglass and resin. It soaks up the excess resin and you can get all of the air bubbles out. Also when you peel the peel ply off it leave a surface ready to primer or adding any filler etc. without sanding. This is a secret we use building full scale composites and it really works great for glassing a model. Don
12-08-2013, 05:45 PM
#1831
12-08-2013, 07:25 PM
#1832
OK Don, I checked out the tutorial. Kool process/procedure. Now for a lesson. I am not a chemist so a little help here. Why doesn't the Dacron fabric stick to the epoxy, is there a plastic component or something within the fabric that prevents the fabric from adhering to the epoxy as it cures? Never seen or touched Dacron. Sure would make life easy when fiberglassing wings/stab - at least. Have you tried it on a fuse? They said it is best for flatter surfaces. Waiting to hear from you. Chic
12-08-2013, 07:33 PM
#1833
Forgot to ask Don, how do you mix up really small portions of the Evercoat to patch a small area? Seems like you need to be very careful of the percentage of hardner and the glaze especially for a small repair to ensure it will properly cure. Tell me how you do it. Educate me again. I enjoy learning. Larry you and Don are correct, I checked about and found the green stuff has small cracks showing. Just did a couple of fabulous turnaround jump shots across the shop with the green stuff. I'll never get rid of the Bondo, smile. Chic
12-08-2013, 09:17 PM
#1834
Dacron is just one materiel that doesn't stick to epoxy. There are others out there but Dacron is cheep and readily available. Evercoat comes in a squeeze bottle so it is easy to control how much to use. I use a piece of glass to mix on as you can clean the glass with a razor blade when it gets to the rubber stage. Or just use a piece of cardboard and throw it away each time. You have to work quickly with Evercoat and use it in very small batches as it flashes off quickly. You will find the best mixing ratio with a little practice. You want it a real light sky blue when mixed. Also for contours you can cut the peel ply in narrow strips and overlap them down something like a fuselage. Don't hurry a glass job. Always let the epoxy cure for 24 hours. Also if you are using micro and resin for a filler you can peel ply that also. when it gets to the rubbery stage you can go in and form it and smooth it with the peel ply. Do try the peel ply process as it will make gassing very easy and light. Don
12-09-2013, 12:14 AM
#1835
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Just to add to pittsdrivers post on peel ply. The technique can be done with regular plastic sheeting. I have used Saran wrap in the past. It obviously doesnt soak up the resin you have to pull the resin from the center to the edges more or less. Another trick I use quite often for "patching damaged CFRP "dings". is to first remove the loose fibers with some sandpaper. Remove the topcoat away from the damaged area an appropriate distance. Then I basically make a "BandAid" out of vinyl tape ( electrical tape also works). By bandaid I mean I cut a patch of tape a little larger than the damaged area and stick it to another piece thats cut large enough to hold the whole thing down. (EDIT: Sticky sides together.) Mix your repair material and fill in the damage and apply the "BandAid". Smooth the bandaid surface and remove any squeezeout. Let it cure. When you peel it off the surface will be darn near level requiring almost no sanding beyond surface scuffing for paint adherence.
Last edited by JWGreening; 12-09-2013 at 11:53 AM.
12-09-2013, 05:08 AM
#1836
OK, OK, I'm going on Ebay to order the Dacron and rush to the Advance Auto Parts Store to purchase the Evercoat. One, can the Dacron be reused or is it now a throw away after each use? Second, about how long before the Evercoat flashes over --- under 3 minutes or under five minutes? Thanks guys for all the advice and information. Certainly will be helpful and useful in this build. Chic
12-09-2013, 05:20 AM
#1837
JW, The whole idea behind using a fabric peel ply is that it does soak up any excess resin so you get just the right amount in the weave. The plastic will not do that plus the peel ply leaves a ready to use surface with no sanding. I use the plastic sheet method to lay up several layers of glass then when it is placed on the airplane I use the peel ply. Chic you get about 3 minutes working time with the Evercoat. Depends on how much hardener you mix in. Just practice with it a few times before you use it on the airplane to figure out a good ratio. Don
12-09-2013, 06:20 PM
#1838
Don, before I pull the trigger, is there a specific Dacron that I should purchase. I see more than one type listed such as Dacron for sails and Dacron for bridal dresses, etc.. Is there a particular place you can send me to in order to buy the right type of Dacron???? I think that is the best idea. Since it soaks up the epoxy, I know the fabric is a throw away item after one use. Thanks. Chic
12-09-2013, 08:42 PM
#1841
Don, before I pull the trigger, is there a specific Dacron that I should purchase. I see more than one type listed such as Dacron for sails and Dacron for bridal dresses, etc.. Is there a particular place you can send me to in order to buy the right type of Dacron???? I think that is the best idea. Since it soaks up the epoxy, I know the fabric is a throw away item after one use. Thanks. Chic
12-10-2013, 07:40 AM
#1842
Don, just followed your lead and put in my order for 4 yds of the uncertified Ceconite lite fabric as you suggested from Aircraft Spruce. I too use West Sys so that I have on hand. Now to get the Evercoat from the local car store. Will set up a test on an old sheeted wing laying over in the corner so that I can give everything (putty/fabric peel ply) a try. Will keep you and the other viewers informed and again, many thanks. Chic
12-10-2013, 07:50 AM
#1843
Hey Guys pass this on. As a previous customer purchasing color chips, I received a letter from GSA saying that GSA is going out of the Fed-Std-595 color products (color chips, color fan deck, sets, books) business. Existing supplies are on a first come first served basis. Really great prices such as, Color Fan Deck was $75 now $20, Color Chips was $5.00 now 50 cents. Email or call Rick Parker (202) 619-8968 or LaFreda McLean (202) 6198925. Just got off the phone with Parker.
12-11-2013, 06:22 PM
#1844
Don, Don - Help. I have found four (4) different Evercoat Metal Glaze Finishing Putty #414, #415, #416, #425 (Finishing Putty, Polyester Finishing Putty, Ultra Finishing Putty). Of course I have no idea which one to buy. Listening carefully to where you direct me. Thanks. Chic
12-12-2013, 02:00 PM
#1845
OK I get it, sorry Don. I now know the #414, 415, 416, and 425 are but the numbers that stand for the size of the product. I am going to order #415 which is the 24 oz. tube. The Dacron has arrived, nice stuff. Will keep everyone posted on this procedure. Chic
12-14-2013, 07:34 PM
#1846
OK guys, again, I have to back up a bit and make another scale correction. The light I put in the port wing is not correct. It is not another landing light. The only landing light is the retractable light also located under the port side outer wing panel which I am also working on. The opening in the port wing leading edge is the light manually operated by the pilot when landing on a carrier so that the LSO on the carrier deck can read the landing approach attitude of the aircraft (Hi, OK, Low). Like a modern VASI, I think that is right. Nowadays, that same light system is completely on the carrier and not mounted in the aircraft (port wing). Inside the small port wing leading edge opening is a green, amber, and red light that is visible to the LSO who is standing on the carrier deck. He then signals to the pilot. his landing attitude. When not landing on a carrier, the pilot does not turn on the light. The FAA (Fleet Air Arm) RAF aircraft had the same port wing attitude light system as the other early Avengers built at Grumman. I'm trying guys to do it right. Chic
12-15-2013, 03:49 AM
#1847
Chic,
Great Progress. Beautiful workmanship.
But alas I'm confused. We put the position lights on the leading edge wing tips and the landing light is kind of centered on the wing.
Charlie must be looking down with a huge smile on his face.
Larry
Great Progress. Beautiful workmanship.
But alas I'm confused. We put the position lights on the leading edge wing tips and the landing light is kind of centered on the wing.
Charlie must be looking down with a huge smile on his face.
Larry
12-15-2013, 05:51 AM
#1848
Hey Larry, believe me, I was even more confused as I did more research. The only landing light is the one on the underside of the port wing. It is located a little more than half way between the leading and trailing edge and roughly in line with the opening on the leading edge that I thought was also a landing light. I hope he is smiling, hope all of you guys are smiling also. Chic
12-15-2013, 07:47 AM
#1850
OMG, yes, I would certainly wish for such a wonderful act on your part. Can not thank you enough. If possible, could you also take a photograph of the rudder & elevator opening? If you and Noah get to D.C. from out there in the wild west, the complete aviation tour is on me. Smile. Chic