kargo

Hey Gang,

What are your methods for sanding fiberglass tape to a smooth finish? I've used thin CA and epoxy for the tape in the past. Thin CA doesn't seem to leave enough stuff to sand smooth, and the epoxy always seems tacky and to more roll strings of glue off than to get smooth.

Thanks

Ram Jet

Maybe you want to try a good quality finishing epoxy or pay very close attention to you mixing ratios. I've mixed epoxy that resulted in a real flexible, rubbery set and sometimes really brittle sets that crack if you just look at it.

Bill

R8893

My Feedback: (20)

I assume you are talking about a joiner strip around the center of a wing. To make your life easier use three layers of 2 ounce cloth instead of one layer of 6 ounce. Make each layer about an inch shorter in the span direction. Put the widest one down first. Three smal lips finish better than the one thick one. I agree with Ram Jet about using finishing epoxy. I prefer NOT to thin the epoxy.
Chuck

HighPlains

My Feedback: (1)

Here is my method which is a bit easier, with very little sanding required.

Now add the center section glass . Use three layers of 2 oz. cloth, with the widest layer on first. Make the first layer widest at front (10-12" tapered to about 5-6" at trailing edge. Second layer is about 2/3" the width of the first, and the third is about 1/3 of the first. Place all three layers on the same time and resin it on with light squeege action. To get a smooth surface, place the wax y surface of wax paper onto the wet resin and smooth out the air pockets. Let it set up, then peal off wax paper and throw away. Trim and sand edges afterward, then do the other side of wing.

You can make this even easier (by wrapping the glass around the LE and doing it all in one shot) if you add a 1/4" to 1/2" strip to the trailing edge to glue the glass too with CA to hold the glass tight while you do the resin or epoxy. After it sets up, just cut away and sand back to the original TE. The wax paper is globally flexible, but locally stiff, so when you smooth out the air pockets, the resin takes the shape of the wax paper and is very smooth with a feather edge. Make sure to put the glossy side against the resin/epoxy, and only use the wax paper once.

I have not found an easy way to remove the wax paper if it is used twice!

Fxrs_tim

Check out the Cold Duck and Blue Angel build threads in the Classic Pattern forum. Mike (RCU name "8178") has a great technique for getting virtually seamless transitions.

Tim

outdoorhunting

Why not use fiberglass resin ? It sands easy & is very strong.

huck1199

What is fiberglass resin ?

outdoorhunting

It is the liquid that you use to "bind" the fiberglass to whatever you are working on. It is the mixture that they use to repair boats, Corvettes, etc. You can mix the hardner "heavy" for make it dry fast, or light to give you more time to work it. It sands much easier than epoxy, I feel it's just as strong. When joining my wing halves together ,I always use the fiberglass at the joint w/ the resin. I've not had a problem yet!!! Also, I use the resin to "fuelproof the firewall area. I just mix it a little light, & brush it on. While I'm at it, I also go ahead & coat the entire fuel tank area in case of leaks. It will flow out really smooth & also adds strength. One note, Use the bolts for your motor mount & coat them with vasoline & screw them into the blind nuts on the firewall, the vasoline will keep the resin from attatching them to the firewall. You can also use it to strengthen any areas that need it. Chop up a little fiberglass cloth so that the fibers are separated, mix them into the resin and apply it, for instance, to the inside corners of your firewall. It will add a lot of strength, but very, very , little weight. Good Luck !! Practice with some mixing cups to get the timing right for drying. The "hardner you use will be in "drops" not oz.

Gray Beard

My Feedback: (-1)

I too use the Resin on glassed center sections plus the layering of the cloth. It works out very well and by buying it in the one quart can it goes a long ways and doesn't cost much. I also buy an extra tube of the part two hardner. I don't ues it for fuel proofing, I use thinned epoxy but only because of the weight difference. Just a lot of different ways to do things, over the years you can tray them and see what works for you.

HighPlains

My Feedback: (1)

Polyester Resin. Stinks like hell, but very easy to work with. Gives a harder surface than most epoxies. Be aware of several things. It will not set up over some epoxies. If you use epoxy on the center glue joint, you need to wipe on a thin barrier layer of white glue. The other important thing is that the hardner will cause blindness if it get into your eyes. If you have kids around treat it like a loaded gun.

outdoorhunting

HighPlains brings up an excellent point. There are MANY things in our hobby that are very dangerous that we take for granted. CA glue, exacto knives, resin hardener, many other things. It would be a very good idea for us to every now & then go through our shops make sure it is kid, pet or even wife safe. My wife never comes into my shop, but the other day she came in to check out my "new obsession" picked up a bottle of CA started shaking it saying" what's this stuff" Luckily the lid was stuck on & wouldn't come off. It could've been a catastrophy

SeamusG

fxrs tim - It would be very helpful to have a hint where in the 43 page build thread the technique is posted.

dhal22

as someone who has reviewed 8178's blue angel thread many many times (i'm building one of my own) it's there somewhere. i recommend enjoying the entire thread, you will find the wing taping technique eventually. but seriously, the edges of the glass need masking tape under them to give you a sanding edge, then apply the glass with polyester resin (lowe's, home depot) and then place a piece of 100% polyester dress liner over the entire assembly and squeegee the resin out. use a smooth roller of some sort to get a smooth finish and peel off the dress liner after the resin has cured. you will have a smooth finish, you can then sand the edges down to the masking tape and you're done (remove the tape of course). works like a charm.

Roary m

My Feedback: (67)

Speaking for myself, I would consider polyester resin as a cologne substitute[sm=bananahead.gif].

outdoorhunting

My wife & I keep a fresh bottle of resin in our night- stand !!!