Varnishing Question

Builder's Forum
1

Hi Everyone, 

My son and I are first time boat builders with zero woodworking experience. Going slow, and with occassional questions to and help from the excellent CLC team, we have managed to do a decent job of constructing our NE Dory.

We are doing some varnishing, starting with the rudder and daggerboard, since it is too cold to varnish the inside hull in our garage right now. I have a couple of questions on which I would appreciate some input.

1.  How long should we wait after applying a coat of varnish before scuffing it up for the next coat? I've been waiting 24 hours but I am hoping that is overkill and I can speed up the process a little without doing damage. We are varnishing in our basement workshop with a consistent temperature of just over 70 degrees fahrenheit.

2.  We have been scuffing up the varnish before applying another coat to provide something for the next coat "to sink its teeth into." Our results so far have been pretty good, but as I was looking out of curiosity for other tips and tricks with boat varnishing on the Internet I found the following. Is this an approach others have tried and did it go well? I am referring specifically to the idea of no sanding between coats of varnish.

"Sanding Tips: No sanding is needed if you overcoat within 48 hours. Don't sand unless the most recent coat has dried for 24 hours. Use 320 grit to prevent scratches; sandpaper finer than 320 grit will not allow proper adhesion. Remove residue before reapplying. Do not use any solvents to wipe down the surface within 48 hours of applying."

Thanks very much.

2

All varnishes are dfferent, so follow the directions on the can.  Some vanishes can be overcoated without sanding, some can't.  Some varnishes dry faster than others.  

If you tell us which varnish you are using, maybe somebody here will have experience using that brand.

   

3

Thank you for your reply, and great varishing work on your boat! I am using Interlux Schooner varnish.   

4

   I have had good luch with Schooner by following the directions.  Weather is relatively warm here in Florida so I usually do a coat in half the boat (top or bottom) first thing in the morning then flip the boat and do other half in the early afternoon.  Next morning I lightly scuff the entire boat then repeat.

I used Epifanes RapidClear on three race boats and on the skiff (pictured above).  It is a semi-gloss that you do not have to sand between coats for good adhesion.  You can also recoat after ~4 hours so 3 coats per day is viable.  In reality, you have to sand after 2-3 coats (depending) to remove all the the little dust/dirt specs that accumulate.  Otherwise, the end product is a bit rough.  

The high glass Schooner definately looks better than the semi when first varnished, but after some usage they both look similar.

In the picture below, 2nd boat from left is Schooner and the other three are RapidClear.