Varnishing question

Twister_Ken

Twister_Ken

Well-Known Member
Joined
31 May 2001
Messages
27,584
Location
'ang on a mo, I'll just take some bearings
Visit site
I neglected to varnish the tiller last season - result, some of the old varnish went flaky. I've now sanded and scraped the tiler, ready for re-varnishing. In some places I'm down to bare wood, in others on sound old varnish.

Should I 'patch' varnish the bare wood first, to build up a coating there, before re-varnishing the whole item, or do I just slop it all over with gay abandon? Old varnish was Epifanes gloss BTW. Intend using the same this time.


----
(edit)
No, I haven't scraped the tiler, I've scraped the tiller.
 
Lynne and Larry Pardey, of whom you may have heard, are varnishing obsessives. Here is something from their web page that might help.

One of their books has a whole chapter on varnishing, including a suggestion that varnishing should be carried out naked so as not to get bits in the varnish. Personally, I'd rather have bits of pullover in my varnish than bits of bodies.
 
Hm pardeys talk about wandering around "touching up" so that'll be manky. Heyho.

Best if possible is to get anything to be varnished off the boat, cos that's the place where the varnish went manky and obv hardly the place where good varnishing gets done. For liveaboards, hard luck - get used to slightly poxy varnish.

The name of the game is prep. That means sanding and more sanding. Fill the holes with whatever, but concentrate on the sanding. Once it's smooth, you still have a week of more sanding cos i want that tiller shiny smooth before any varnishing at all, right down to flour paper smooth, pretty much like glass, before varnishing. It needs to be flat like as if the thing as made of glass or plastic, before getting on to the next stage.

Oh, and of course, all sanding needs a sanding block, not just in your hand unless you're fine about it being poxy, and i'm not, so get a sanding block, and if there are fiddly bits you have to make a sanding block for those, that's what the aprentice does or you if you have no apprentice. If no sanding block, expect a homemade-not-quite flat finish that is smooth but not truly flat because you've dug out the softer areas/ deeper bits and ridden over the harder high spots, the opposite of what you want to do, like people who roll a not-already flat lawn actually make it more lumpy.

Sanding blocks are made of soft plastic, soft wood, or an eraser can be ok, or cork also ok. For curved things you may need a slightly concave sanding block made from a sawn-up section drainage pipe etc.

You sand and sand until it's perfect with that bit of sandaper, and always generaly with the grain. You have done with one grade of paper when your sanding slightly one way is immediately oversanded by sanding another way.

As you move from one grade to a finer grade, "warm" any new sandaper by rubbing two sheets together a bit.

Most people get things nice and sanded inthe big flat areas, but bit rubbish in fiddly areas. Concentrate on those fiddly areas. ESPECIALLY hard are end grain bits, and these take loads longer to get very flat and very smooth.

Now it's al flat and supersmooth so it's almost waarm t the touch, the next stage is "turning the grain". You know how matches or cocktail sticks bend in water a bit? The same hapens to wood the moment you varnish. Which is another reason why most varnsh a bit manky. Turn the grain with damp rag, and smooth down again and again until damp rag doesn't make it rougher. This can take a few days.

Varnishing should be done on warm day before noon (cos condensation begins afterwards) or (better) indoors in an empty warm and still dustfree room that you can lock/leave the moment finished varnishing.

Use the varnish from a new varnish pot: open tin, pour vanish into pot, close tin. Then no bits ever get into pot . NEVER put brush into tin for perfect varnish. Sack any painter who puts a brush into a tin cos this is first week of apprenticeship lesson.

You can make varnishing pots from sawn-off bottoms of evian bottle or other super-clean throwaway containers. New container each coat.

The brush needs to be swelled before use. Use a fab expensive brush, not a throway cr ap one. So this means not a new brush, or if it is a new brush, give it a good battering to get rid of loose hairs. Soak brush overnght before varnish day. It's almost never varnish day, by the way. You skipped on the sanding, and only turned the grain once instead of getting the wood shiny before varnishing, didncha?

So anyway first coat, shut door so nobody walks in ooh that's nice dear. Varnish nice and fast, and area by area: decide how much each brushload of varnish will cover, wham it around sideways, use tip 1inh, not whole gloopy brush and lay ff with raggy edge for next.

When done, take brush out to clean, lock door on workpiece. You can thin this first coat but it's gonna get sanded right back anyway so don't fret. I am not keen diluting varnish, really. But v keen on sanding.

Probably 36 hours minimum before sandable, and sanding has to be done between every layer with v fine flour paper, and those sanding blocks. If possible, don't sand in the same room as where you varnish.

Don't even think of counting the number of layers cos it's loads: keep adding layers until the next layer makes no differerence.

Other option is to just slap the varnish on any old how and do the proper varnish another year....
 
Patch? Jeez. You either sand the whole thing down to perfect varnish or perfect bare wood first - and do the same before every coat after that. If you have a base layer of some old varnish, and some new varnish, it'll probly be a bit rubbish. Or not perfect. You can try the patching idea, but unlikely to get to a perfect base, imho.
 
I've had some success patching, although I know I have to do a TCM if I want perfection (Problem is, I'd have to kill the person who put the first mark on it...)
I lightly wet-sanded with a block to identify the low points, then filled them with varnish, then repeated to the power n, where n is a large positive integer.
The result was pretty glass-like apart from the suspended dust (liveaboard!)
You'll see the paid help running about with a jamjar of varnish doing just the same on the big posh yachts.
 
Patch coat of thinned varnish, preferably several of increasingly 'less thinned' viscosity, is fine IMO. Just key each surface with 180 and recoat. No need to cut right back or use fine grade. Soon you'll not see the join! Take a bit more care on final coat prep. Use a tack cloth, high quality brushes/foam brushes - but you'll know all about that.
 
[ QUOTE ]
Sand it down to bare wood before every coat. Shurely not?

[/ QUOTE ]
it is best practice to sand back to the wood, this will give you an even finish with little to no colour variation.
It is personal preference what you do. adding it to the surface you have now will not give you the best result but will do the job, you are best to ask yourself what you want, perfect job or ok job.
i would go for sanding it down all the way to the wood. it is not that much of a big piece of wood that would take a long time. the reward will be seen by all /forums/images/graemlins/smirk.gif
 
Yes, you've just reminded me of all the reasons why I no longer have a boat with any varnishwork.
/forums/images/graemlins/laugh.gif
 
Ken, to save all this aggro, cover the tiller when not in use. Also, remove it and stow below over the winter. If you keep her afloat, a cheapo bit of 2x4 will do for those winter outings and keep the rudder straight on the mooring.
 
Its a tiller, not exactly huge is it?
Sand it back to bare wood all over, forget patching, it will not be the same, the wood will have bleached below the varnish and patched bits will look......................... well patched!! Follow TCM's instructions and make a lovely job of it, nowt looks better than a really lovely wooden tiller. Feels nice too!!
 
You must log in or register to reply here.

Share this page

Top