a good glassed finish ??

[Arbo]

Ok, I working on a plane now, and want to have a nice smooth finish, It's going to be glassed, but I want to make sure I do this right. I plan on using polycrilic (as that's what I have read about using and bought) and the glass, but I have a few questions for anyone out there that has done this before...

I have messed with glassing stuff before, but just a bit, and I used some scraps as test, after putting down the cloth and poly and letting it dry, you can still see a rough weave surface.... I know you need to sand but what is the process? Sand a bit, another coat of poly, sand poly until you get a nice smooth surface then paint?

I was testing with .75 oz cloth, and it seemed it didn't take much with some 320 grit and the cloth was gone... hence I'm worried about sanding it all away...

Thanks for ideas/comments in advance..

Paul

[gregg f]

Paul: this is how i do it.
http://home.fuse.net/ryan/glassing.htm ...............gregg

[Andy W]

If you want a glass-smooth finish, perhaps glass cloth is not a good choice for covering? Filling and sanding will result in more weight. If weight is not the issue, however, you can use a lightweight filler (spackling) to fill the weave, then coat this and paint it..
..a

[steve lewin]

Lightweight glass cloth and epoxy will readily give a super-smooth finish but I'm afraid I've no idea what "polycrilic" is. If it sticks and sands as well as polyester/epoxy resins it should be o.k.

The trick is to fill the weave of the cloth and then sand very lightly (I've used 400 wet and dry used wet for epoxy). You don't really want to cut the glass at all, you should just be sanding resin but it's tricky to avoid the glass unless you use far too much resin, which adds too much weight :(.

I confess I usually use old-fashioned tissue and dope which gives a similar finish without much trouble (except dope is smellier than epoxy resin and almost as bad as polyester resin).

Steve

[radfordc]

Originally posted by Arbo
Ok, I working on a plane now, and want to have a nice smooth finish, It's going to be glassed, but I want to make sure I do this right. I plan on using polycrilic (as that's what I have read about using and bought) and the glass, but I have a few questions for anyone out there that has done this before...

I have messed with glassing stuff before, but just a bit, and I used some scraps as test, after putting down the cloth and poly and letting it dry, you can still see a rough weave surface.... I know you need to sand but what is the process? Sand a bit, another coat of poly, sand poly until you get a nice smooth surface then paint?

I was testing with .75 oz cloth, and it seemed it didn't take much with some 320 grit and the cloth was gone... hence I'm worried about sanding it all away...

Thanks for ideas/comments in advance..

Paul

First, you need to get the balsa surface as smooth as possible. Sand with 220 grit and fill any dings with lite spackle. Put the .75 cloth on with Polycrylic. After the first coat don't go heavy on the sanding or you will sand through the cloth. Just a very light sanding with 220 or finer paper. It will take several coats of WBPU to get the cloth filled. You will still see some of the weave even then. If you want a mirror smooth finish, you need to finish with a coat or two of primer and then sand almost all the primer off. As long as you sand off most of what you put on, the weight build up shouldn't be excessive.

Charlie

[ifrichard]

My 2 cents,

Although, I use a lot of epoxy, I recently discovered wiping the epoxy off with a paper towel or tissue. I had been using plastic Bondo spreaders or playing cards and was always disappointed with the irregular flow of the epoxy. Wiping off the resin is a critical step in keeping the finish light yet smooth. The URL that Gregg mentioned does cover this step.

Another tip is that when sanding epoxy, you must choose the appropriate mix. Some epoxy formulas are not suitable for sanding. The easier that the epoxy sands the less likely you will be to go through to the glass. If I wanted a really smooth finish, I would probably top coat with a different epoxy mix than I used for the glassing.

Good Luck, Richard

[Joe Elston]

I use West Systems Epoxy for all my planes that I glass. With 3/4 ounce cloth it comes out very smooth and is very easy to sand. The first coat is just to lay out the glass so you dont need to fill the weave of the glass. Then I apply a very light second coat . Then you can wetsand it before you prime. If done right it comes out very smooth and not very heavy. I also use a combination of paper towels and squeege to remove the extra resin. Some people thin their resin but I don't seem to need to with the West Systems. If I do I use Denatured alcohol.
Just my two cents
Have fun:D
Joe

[Arbo]

I appriciate all the good advice... come items are don't use too much, get the excess off, and sand lightly as to not remove the glass....

I already started on the mig, but it seems I didn't do a good enough job with the putty... I'll crack it up as a good first learning experience, the next one will be better....

Once again, thanks for the advice...

Paul