eggsmartha

Is there a rule of thumb to use on how much epoxy to mix at a time, obviously it is dependant upon how large a surface is being convered. I am going to use 3/4 oz fiberglass to cover an 82" span p-51. if i do a 42" wing section at a time, that's about 600 sq inches. about how much epoxy would be used with this area?

cactusflyer

My Feedback: (4)

With regard to heating epoxy, I've found that heating the part...not the epoxy works MUCH better. It's amazing how a little heat will kick off the the epoxy when you heat it in a container.

Johng wrote: "I was experimenting with heating it in the micro a few years ago, no kidding( I'm not married ). 5 seconds on high is plenty for one batch. It will be watery and set in a couple minutes. 3 seconds would probably be a better temp.

I tried 10 seconds once, hee, hee. It went exothermic in my hand while I was walking from the micro to the bench and had to pitch the stuff into a wash basin to keep boiling epoxy from foaming over onto my hand. Man, that was stupid".

Thank you for that!!........that's the first positive correlation between this hobby and being married that I have heard! My life just became better!

Anyway, back to my $.02 worth.... when you heat the part before application, the epoxy hits it and flows out nicely. If you have warm epoxy flowing onto a "cold" part, it tends to "freeze" on contact.

Tailwinds,


John

ajcoholic

My Feedback: (10)

West standard resin with the slow hardener is allready quite runny.

I find it will soak right through thin veneers (I use it to glue on wing skins onto foam cores) at room temps, so I have not had a cause to thin and/or heat it.

The resin and hardeners will thicken over years, as West sytems is good for many years shelf life it may be necessary later on. I buy mine in gallons and use it fast enough as fot that not to be an issue. If you will not use it up in a year or two you may want to get the quarts instead. I find the fast hardener is thicker than the slow, and ages a lot faster also.

AJC

doctor jason

As with all Epoxy resins if you need to thin it down you can use heat from a hot air gun, however when working with larger surfaces it is better to add 10 % methanol this will give a thinner epoxy and does not effect the curing time of the resin.the methanol will thin out really well just like the hot air will do and has the advantage that it will remain thinner unlike appling hot air which once the hot air is removed the resin will thicken again in seconds.

F9F Texan

I finally got around to trying West System's #105 finish epoxy..

All I can say is..GREAT!

This is the easiest sanding epoxy I've ever used. I didn't squeegie it well enough on the first 2 or 3 surfasces I tried it on, and was really dreading the chore of sanding the excess. I was pleasantly surprized at how well it sand. It cures to the touch in just a few hours, so it seems that you could do both sides of several panels in one day's work, then sand and finish the next day.

On another note:
The attached picture shows why this is a good day for this kind of work. A strange sight in a suburb of Dallas, Tx.
Johnny

BTW: I used the epoxy straight out of the can at room temperature.

bruno-dude

I am building a Piper Arrow 2 by Aviomodelli. Have never glassed before except to practice last night w/Zpoxy. Worked ok on ply and balsa. But this plane has vinyl covered foam wings. I think it should adhere but don't want to assume that West Systems Epoxy will adhere to the vinyl?

I also have a couple other questions. I haven't seen anyone address this first question in multiple threads I've read. Once I have covered the bottom wing panel don't I have to overlap the cloth a little when covering the top panel and won't that leave a ridge? Does it sand off evenly? Finally, any suggestions on how to cover the fuselage as far as what sections first, overlap where, etc? This is obviously much less of a concern if it sands down smooth where I have overlapped sections of cloth.

Thanks for any info!

Johng

My Feedback: (4)

I'm not familiar with this kit. Is there a web page? However, I'd speculate that if the wing already has vinyl covering, you shouldn't be glassing it.

bruno-dude

This is the address to the plane and an American distributer. I am trying to spray w/latex for paint and am not sure how else to cover. The plans call for 2 coats of sanding sealer but latex won't stick to that cause it is oil based. Also the leading edge is balsa.







http://www.internet-rc.com/pipar2byav.html

bruno-dude

Could I just use a sandable auto primer?

Johng

My Feedback: (4)

The vinyl thing is confusing without being able to actually see the wings. You say the wings are covered with vinyl, but have a balsa leading edge - is the LE not covered?

Do you think the vinyl was intended as the final covering? Epoxy will not stick to it.

If you must paint the wing, I would try to light sand it to remove the gloss then go with either primer or straight to paint. My best advice would be to find a way to finish it with just the vinyl on the wings.

My advice on glassing the (wood) fuse is to go ahead and overlap the pieces and then sand the seam down. Just make sure to use the minimum epoxy possible at first. The glass pattern should still be obvious after the epoxy is applied. THen sand down to remove the seams and other problems. Then apply filler to large imperfections and resand. Then you may apply another coat of epoxy to fill the weave. Sand again and go to primer. Sand and repeat primer/sanding until you have the finish you want. Sanding should remove alot of the priimer each time so that only the weave/gaps get filled until the final coat.

bruno-dude

Thanks, John-

Here is a picture to try and show the vinyl wing. Pretty but how to cover it!! I have never seen anything like it before. The vinyl is probably 2mm thick and laminates over the foam very well.