Sanding between coats of spar (marks in finish, oh no!)

[K. Mogensen]

Hey, started spraying my bow with satin spar yesterday. Got the first coat done, and waited all night to bring it in from the shed (freezing in there). I didn't want to be grabbing the bow while it was tacky.

When I went out to get it, it felt more or less dry to the touch, so I brought her in.

Thanks to the sudden temp. change, there was some fogging on the limbs that I tried to wipe off with a rag (remember the bow didn't  feel tacky) and whaddya know: wipe marks all over! Not bad, you can only see them when the light shines a certain way, but I'm disappointed in myself.

So, before I boo hoo too much more, can this be saved? I was planning 2-3 light coats of the satin spar (I've already done tru oil underneath) but hadn't been planning on sanding, to keep the frost texture. My first was fairly light and not totally even. I'd hoped the next coats would take care of that.

Should I just spray the next coats and the marks'll go away?

Or should I sand before spraying again?

OR, should I sand it all and start over? (The last is rhetorical, I put 14 coat's of tru-oil on it, and I'm NOT going back).      

So, please pardon the ignorance and incopetence, and help me out.

God I'm stupid sometimes...   :rolleyes:

[dfrois]

I'm sure more knowledgeable folks will chime in shortly, but in the meantime, I will tell you what I would do. I do not know what "spar varnish" is, living in Europe, but I have some experience with several types of varnish on woods, and, if the marks are not deep, I would try to sand them with a fine emery paper (600 or more), trying to avoid breaking through the layer of varnish. The goal is to even the surface, not removing the varnish. Think of eliminating only the high spots of the finger markings. If you can do that, and get an even-looking surface, then the next layer of varnish should eliminate all traces of the markings.

And, since this has just happened last night, please let the varnish dry well before trying to fix it. Most varnishes and paints I know go through a fase, during drying, where the surface is dry but the innards of the layer is still soft, and touching it then will deform the layer, even if the surface is not broken. So, dry well before  messing with it. Placing it in a warm place will speed up the drying, but it will also exacerbate the difference between the dry surface and the soft thickness underneath.

Just my two cents, of course...

DF

[Robertfishes]

I have to use a dehumidifier in my spray room here in Florida for the first day..lots of humidity here. On cold days I have to run a small heater too..I still have to wait at least 4 days for the spar urethane to cure before I can sand it. I tried to fix a small run once after a day of drying, it gummed up the sand paper and made a mess, wait for the spar to cure/harden before sanding.

[K. Mogensen]

If I do sand, what grit should I use? I was gonna let it cure until Wednsday too.

Thanks guys.

[Troy D. Breeding]

Spar Urathane is a very slow curing finish. I've used it several times and found that it needs atleast 3 days to cure before any sanding.

If I remember right the brand I use say recoat within 2-3 hours or wait atleast 72 hours and lightly sand then recoat.

Once I have the finish looking like I want I wait atleast 5 days before handling or shooting.

Troy

[K. Mogensen]

Yep, 72 hours. Wednsday puts me right there.

On my last coat of tru oil I was wetsanding with 2000. Should I use that between the spar? I know 600 grit was mentioned, the closest I've got is 450 and 800-wetdry. Is there one that'd be better than the other?

Thanks for helping.

[Troy D. Breeding]

I've never used anything smoother than 400. Back up,,, I did try some 600 one time and it was almost like doing nothing to me. JMHO....

[LittleBen]

This reminds me how I love and hate spar varnish. I desperately try to recoat withing that 3hr window to avoid sanding, and I usually give a week to cure after that. I've used it alot on wooden sailboat parts and man is it water resistant. Done a few bows with it too ...

[Sixby]

Since you are shooting over 14 coats of tru oil I would let it completely dry. sand with 4oo wet and dry and a little water to lube it. Just sand until smooth. wipe dry make sure there are no marks , fuzz ect and reshoot with a thin coat of your Spar Var. Let dry in warm room  a couple hours and reshoot. The big mistake is to not use heavy enough sandpaper to make it stick and to shoot too heavy a coat to start. Just make sure it gets wet with the finish. That is good enough for the first coat.

God bless you and good luck. Steve

[K. Mogensen]

Thanks guys. Tomorrow is the day of reckoning so I'll see how it turns out...

[K. Mogensen]

Wetsanded today and sprayed. Looks good. Seemed to be dry enough (no 'gumming'). Marks are gone, and though the finish is still a bit uneven, I think the next couple coat's will even out and really look good.

Thanks again guys! Really appreciate your help.