I started doing a little sanding tonight after glassing last week. The stems are a little rough where they are layered. When I feather the edges I start to hit raw glass. I suppose this has to happen when feathering the layers, right? Do you put another layer of resin over this prior to the finish varnish or varnish over the small areas of raw glass?

Thanks

On my Ranger build, I laid several strips of glass cut on the bias (like shingles) over my stems. I did this after I glassed the entire hull. It was an after thought and if I did it again, I think I would lay up my bias strips first and then cover them with a full sheet of glass.

But, regardless of how you do it you have to sand into the glass to feather. When I was satisfied with my feathering, I covered the stem area with epoxy to fill the weave in the bias strips and coat the sanded glass. When you do this, you will probably brush epoxy onto cured epoxy. So, make sure you roughen enough area of the hull to provide tooth for the new epoxy that you are laying down.

I have a picture of my stem before feathering. It looks rough, but when I was done you could not see the layers of bias strips.

stem before feathering

I used 3 layers of 4 oz cut on a bias over the main layer. I feathered out with a couple extra coats of epoxy and it turned out great.

The best scenario is to lay your bias strips on top of your main cloth.
Feather the edges within about 24 hrs with a scraper. Varnish will cover the bias strip edges. Making them near invisible.
No need for more epoxy.
Lay your bias strips widest one first. I use two.
I do this just after wetting out the glass.
I can testify that this works !

Jim

This is my first build so I'm learning as I go. My bias strips are under the main sheet. I did do a little feathering after the wet out to knock off the bigger nubs at the edges. I realize it would be a bad idea to sand thru the main sheet to get a perfectly feathered edge. I am thinking my feathering won't be perfect but I will end up with some raw fabric showing thru (have already)unless I build up more resin and feather the resin.

Here's a couple of pics of what I'm talking about. On both stems and in 2 places on the hull, I've sanded thru the resin to the glass in small areas. Should I put another coat of resin on?

Resin is not necessary, and will not add strength to the thinned areas.
The varnish will cover and make the weave invisible. It amazed me the first time I had this same problem. Clean it good with compressed air, or a good vac.

Jim

Well I will weigh in again. In your #2 of 3 photos, I see a problem that varnish alone will not cure. The spots that are glossy are low areas. You are not done with feathering. If you varnish now and do not fair out the hull, those low areas will always show (given the right light angle). Fair it out, put on a coat of epoxy (not for strength but for filler), sand it, varnish it, and ya got a good job.

Since the bias strips are under the main cloth, feathering anymore will thin the main cloth. These pics show why the bias strips
should go on top.
If you are going to put another layer over the bias strips and the main layer. Feather what you have now.
Feathering is better done by scraping than sanding. Sanding creates dust that ends up in the pores of the cloth and resin, and will show up after varnishing.
Epoxy alone will not add strength.

Jim

Thanks fo all the replies guys. Is it ok to put another resin layer down with 80 grit swirl marks or should i go finer? Will the sanding marks show thru the added resin layer?

I'd go lighter grit.