Varnishing technique

[Alan Gage]

Curious to know what everyone uses for a varnishing technique and how well it works for you. General varnishing techniques welcome but I'm mostly concerned with varnishing a canoe hull. Also, what varnish do you use and what are its characteristics (how thick? how fast does it set?).

When I varnish I jump back and forth from side to side. I'll start in the bow or stern, do two feet on one side of the canoe, jump to the other side and do two feet, then back over to the first side for the next two feet. I quickly brush it on pretty heavy with horizontal strokes, then vertical strokes to even it out better, and then light horizontal strokes to finish it before switching sides. I normally use a 4" foam brush.

This works ok but I always struggle with keeping the wet edge wet enough. It only takes me about 1 1/2 minutes per side but even in that short amount of time I have trouble blending the areas where brush strokes necessarily overlap the last section. They don't always self level as the varnish has already started to gel.

Does anyone use the technique where you put tape down the center line of the canoe and varnish one side of the canoe at a time? This would help with the wet edge problem but would add more days to the process and I wonder how the center line blends together at the end.

I'm using Minwax Helmsman Spar varnish. It obviously sets up pretty quick so I can do multiple coats in a day. It's quite thin and readily runs on a vertical surface it the coat is too thick. I think I'd like something a little thicker and slightly slower setting.

Alan

 

[Boatman53]

Alan, I use Interlux #96 Schooner Varnish as my all around varnish. I have two customers that ask me to use a different kind but I prefer the Schooner.
You can't do multiple coats in a day but when I really need it to dry in a hurry or in cooler temps I add a couple of drops of Japan Drier.
My strip built guideboat has somewhat hard corners where the side meet the bottom board so I pick one side or the other to use as the join line and I varnish one side then the other. I do not use tape, I just brush to the corner and on the return trip I brush up to the wet edge and it blends well enough you have to look for it to see it. A canoe is different an I do as you do, a foot or so on one side then cross the middle and catch up and extend the other side and back and forth down the hull. I use t good badger hair brush about three inches I think I would have to look. I do use foam brushes for small jobs but nothing beats a badger brush with lots of bristles. I brush in the direction of the grain only and as little as necessary to lay on the varnish. On bigger projects like a mahogany runabout I'll get some help, the helper rolls on the varnish with a foam roller and I tip it out in the direction of the grain. I alway do the brushing as I can add or remove excess varnish if they put it on too thin or thick. I sand to 220 grit and then give it a going over with a maroon scotchbrite pad, tack and varnish. Been doing it that way for thirty years.
Jim

 

[frozentripper]

Wouldn't a thicker varnish result in thicker coats and be more prone to runs and drips... I've used Interlux Schooner in the past and it seemed kind of thick, forming runs easily. Interlux (and other brands IIRC) recommended thinning for the first two coats (brushing liquid 333 is their thinner)...

Brush/Roller: If Clear Wood Sealer has been omitted, apply the first coat thinned 50% with Brushing Liquid 333, second coat 25%. Following coats can be applied without thinning or can be thinned 5% with Brushing Liquid 333 if needed. Apply a further 4-6 coats, until a satisfactory finish is achieved. Sand after every second coat* using 320-400 grade paper. Remove sanding dust with a dust wipe.

... but I still found it forming runs down the sides of the hull. Those "levelling agents" in the varnish mix are said to help smooth out brush marks but runs still were happening.

There is a new formula IS with improved leveling agents so maybe they've been working on that. IS also had some exotic fragrant oil mixed in which was nice at first but a year or even several years after varnishing the canoe would heat up in the sun and that perfume would start wafting out, polluting the natural smells at the shoreline and campsite... eg. paddling by a cedar shoreline.

I've since switched to Defthane Exterior which is thinner right out of the can, doesn't smell perfumey and doesn't need thinning. It brushes on thin quickly, more smoothly with fewer runs than IS and at half the price, gotta like that.

 

[Boatman53]

Thinning is recommended for the first coat or two when varnishing raw wood to help it penetrate the surface. There is no penetration in fiberglass so no need to thin.
Applying as thick a coat as possible that doesn't sag is desirable. Brushed too thin and you have to apply more coats or failure of the finish is the result. I have some boats I've looked after for more than 20 years. They get one coat of varnish in the spring and if they live outside in the winter or head south they get another coat in the fall. The boats I store inside just the one in the spring. In twenty years I've never had to strip and start over, but I see other varnishes having to do that every couple of years.
Jim

 

[dogbrain]

Thanks for posting this Alan. I had the same problem as you using man-o-war varnish and keeping the wet edge on either side, but I assumed it was our really dry climate that made the varnish dry so quickly. Since you live in a relatively humid climate it sounds like that may not have been the issue. I used Helmsman for the inside of my boat because it was cheaper. It's difficult to see the dried brush marks on the glass weave, but they're there. I thought about running a humidifier in the shop while I'm varnishing on my next build. I look forward to hearing other possible solutions.

Mark

 

[Boatman53]

Too much humidity will knock the gloss down somewhat. I rushed a job one time, it was July the temps were in the 90's and the humidity was in the 80% range. I had to do the job over as the job just didn't have the shine. I don't varnish in those conditions anymore, that was an expensive lesson for me. 70° with 50% RH is ideal.
Jim

 

[frozentripper]

Just a thought if that perfect finish is needed... Helmsman varnish is also available in spray cans, several will be necessary.

http://www.homedepot.com/p/Minwax-1...r-Spar-Urethane-Aerosol-Spray-33260/100199613

 

[memaquay]

I use Helmsman too, and went through a variety of methods. My current one is to use a foam roller. Puts the varnish on very thin. I tip out the air bubbles with a foam brush. In this way, I can do an entire canoe in about 15 minutes. I do two stations on a side at a time, alternating back and forth. Haven't seen a run in quite a while since doing it this way.

 

[sweeper]

There is also a water based Helmsman that we spray on our Barrel Stave Chairs.

I have finished the inside of a canoe yet but I always thin the first few coats.

 

[pblanc]

I have found that in my hands at least, Minwax Helmsman Spar finish (which is really a urethane) is somewhat more prone to runs and sags when applying it to a vertical or near vertical surface.

I have generally used Pettit Z-Spar varnish, either Captain's or Flagship, but I have also used Interlux Schooner varnish. I would say that the Z-Spar Flagship gives the best cosmetic results but can be a bit trickier to apply than the other two. I don't thin the varnish.

I usually use a 2" wide disposable foam brush, and brush in one direction only. I have found that in order to maintain a wet edge, it is best to run a line of masking tape down the keel line of the canoe and do one side at a time. I wet sand between coats enough to dull the surface gloss and I have used anywhere from 400 to 1500 grit for this purpose and haven't noticed much difference in results between the various grits.

 

[Canotrouge]

This is a good video, he has a few other one too!! https://www.youtube.com/watch?v=711AfDTuqvk

 

[yellowcanoe]

Epifanes Clear Varnish here. Not too runny.. Sploosh and swoosh with the grain of wood.. never across never rework it more than once. Expensive and well worth it.

 

[Guest]

I use Helmsman too, and went through a variety of methods. My current one is to use a foam roller. Puts the varnish on very thin. I tip out the air bubbles with a foam brush. In this way, I can do an entire canoe in about 15 minutes. I do two stations on a side at a time, alternating back and forth. Haven't seen a run in quite a while since doing it this way.

Pretty much my “technique” as well, at least for coating a hull bottom.

I use Helmsman Spar urethane, a short nap foam roller and a foam brush to tip it out. I don’t bother with tape edge along the keel line, I just roll out one half-side (past the center line a bit) of the hull from stem to stem, go back to the far end and tip that side out with the foam brush, roll out the other side, and tip that out.

I can see no visibly overlap of varnish (sorry, urethane) on the bottom of the canoe when I am done. It’s the bottom; I’m gonna scratch that up next trip in any case. That application, even with thicker than varnish Helmsman Spar Urethane, is thin enough that I usually apply a second coat rolled/tipped the same way.

Without a timely tip out the roller application will leave a bit of orange-peel finish. Given my druthers I’d prefer to have a tip-out helper follow along some minutes behind me after I do the roll out. But, doing one side at a time, even working alone, I can do a full hull in 10 or 15 minutes (plus 20 minutes of boat prep protective taping along the outwales).

I have found that in my hands at least, Minwax Helmsman Spar finish (which is really a urethane) is somewhat more prone to runs and sags when applying it to a vertical or near vertical surface.

Yeah, Helmsman goes on thick, and for something like a paddle, hung vertically to dry, can be a saggy mess even with after post-application attentions. I still use varnish on most refurbished paddle blades for that sag-less aesthetic reason.

Is there a way/product to thin “spar” urethane? I have never done so, but I’m not averse to multiple coats in any case.

The advantage of Helmsman is that it is inexpensive, available in any hardware store, and proven both durable and UV resistant.

http://www.myccr.com/phpbbforum/viewtopic.php?f=49&t=40923

This more scientific test conducted by the Practical Sailor confirms those results:

“One hardware store varnish has surprisingly held its own over the long haul: Minwax Helmsman Spar Urethane. At half the cost of the recommended one-part varnishes, Minwax slacked in the color retention department, but it has proven its multi-season durability”

http://www.practical-sailor.com/issues/37_9/features/exterior_wood_10576-1.html

Helmsman Spar Urethane is good enough for me, and if I need to recoat it down the road I can find another can of the exact same stuff at any hardware store, to put like material atop same.

Epifanes Clear Varnish here. Expensive and well worth it.

I have a full, unopened 1000 ml can of Epifanes Clear Varnish in the shop, labeled “High Gloss, extra UV-filter”.

I’m saving it for something special.

 

[Alan Gage]

Mike said:Yeah, Helmsman goes on thick

Is there a way/product to thin “spar” urethane?

I always thought Helmsman was thinner than most other finishes and that was the cause for it being prone to runs. A thicker finish seems to be able hold itself together better when applied thicker. The Helmsman has to go on thin or else it runs due to the lack of viscosity. To me it seems like it's easy to put on a thin coat of it but I need more coats in total to compensate.

I've never felt the need to thin Helmsman but you can thin pretty much any finish by mixing it with whatever product is recommended for cleanup. So in this case that would be mineral spirits. If you wanted to thin a water borne finish you'd use water. Adding solvents can slow the cure time as it's one more thing that has to evaporate before the finish can dry but the thinner coverage might counteract that.

All cans of oil based varnish say not to thin. I read a couple in depth books about wood finishing a few years ago by Jewitt and Flexnor and both of them made the point that the only reason for that was because the manufacturers have to formulate their finishes to meet VOC requirements. As soon as you add a thinner those requirements are shot to heck. They don't want a manufacturer to skirt the rules by canning a product that meets requirements and then instruct you to add thinner to make it usable.

These are both really good reads on the subject. I learned a lot. Mostly that marketing wood finishes is a bit like a shell game in that you never really know what you're getting and the manufacturers don't make it easy for you to find out. For instance good old Formby's Tung Oil isn't even tung oil but rather a wiping varnish (which is nothing but a heavily thinned varnish). They do a nice job of breaking down the different types of finishes, the benefits/drawbacks to each, and how to spot what's what by reading the labels.

https://www.amazon.com/Tauntons-Comp...FNACSQBHJRQSBA

https://www.amazon.com/Understanding...sap_bc?ie=UTF8

I sure am glad I started this thread. Some really good ideas presented here. Much appreciated.

Alan

 

[Pook]

Alan,

Sounds like you already found your answers but to add, Mike Elliott wrote quite an informative blog about varnishing canoes back in November- including the myths about thinning varnish. Lots of useful info in there.

https://canoeguybc.wordpress.com/2016/11/

Cheers!
Bruce

 

[Guest]

I always thought Helmsman was thinner than most other finishes and that was the cause for it being prone to runs. A thicker finish seems to be able hold itself together better when applied thicker. The Helmsman has to go on thin or else it runs due to the lack of viscosity. To me it seems like it's easy to put on a thin coat of it but I need more coats in total to compensate.

It may be something other than thicker/thinner or viscosity.

I’m thinking here mostly of use on wood paddle blades, where spar urethane seems more prone to drips and sags. It also seems as though two coats of Helmsman is plenty thick while I would want at least 3 coats of real varnish, even with a minimal thinning schedule.

It may also be that urethane is simply harder to thin-coat apply when trying for a good looking blade finish, or real varnish is more forgiving of my sloppy brush technique.

Mike Elliott wrote quite an informative blog about varnishing canoes back in November- including the myths about thinning varnish. Lots of useful info in there.

https://canoeguybc.wordpress.com/2016/11/

There is a lot of good explanation and myth busting about what shellac, varnish and oils actually are and do in that Blog. His finishing schedule is not for the hasty though.

Step 1: Apply a coat of the oil/turpentine mix to the entire canoe and let the oil dry for a couple of weeks

Step 2: Apply shellac, wait to dry, fine steel wool, vacuum, ready for varnish.

Step 3: Apply thinned varnish using $50 brush. Tip out. Wait 48 hours (for re-coat?)

Step 4: Normally apply two coats of shellac and three coats of varnish.

Hopefully the two coats of shellac go on at the same time, and not two week’s dry time in between, otherwise I would need a separate drying room off the shop just for the month’s wait time.

 

[Pook]

Fair enough Mike, the oil/turps mix restores the dried out brittle wood. May not be necessary in all cases.
And in my experience with Shellac is that you can re-coat within a couple of hours.
So you're maybe looking at 4 day process in total. (2 coats shellac and 3 coats varnish).
Bruce

 

[Iskweo]

I have different grades of varnish depending on the job. You can get satin or gloss finishes in the Helmsman and I do use it on the less expensive boats, or as an initial coat that soaks into the wood. It is an ok all around varnish and it keeps well once opened. I like to use this for the outside of the hull, instead of oiling the wood.

Then we have the good stuff. Epifanes. Twice the price and well worth it for your favourite projects. We use it on all of our resale / restoration work. It is tough, has good coverage, and I love the nice amber colour it gives the wood. I have used it over the Helmsman with good results. My one b*tch about it is that once the can is opened it is tough to get it resealed to the point where it stops curing. I tend to use the whole can so I dont have hard dried out leftovers. You can thin it out though and use that for initial coats ...it's just not good to keep long term once opened.

As for technique, I just start at one end and work to the other. One pass and maybe one later to catch runs / sags. The Epifanes tends to be thick and can pool...you have to tip it to clear that up. Really though, I just take my time, I am never in a hurry. I keep the wet edge advancing slowly while I check back for runs etc and clean them up as I go along. Helmsman is runny but hey, I am using that mostly for thinned out initial coats so a bit of mess is expected.

Nothing special for brushes...just not bargain basement stuff. I have not tried the roller method but then I mostly do w/c so brushes tend to work better there. Rollers would be good on strippers though for sure. I think we did do that on a stripper....ask karin. Probably on Mem's advice.

Finally.....I never pass up a can of varnish of any sort at garage sales and such. You can use the cheaper or no brand stuff for all sorts of things that Epifanes would make you lose sleep over.

As luck would have it...I have 112 rib tips and some inner gunwales to do second coat on this weekend.
.
Christy

 

[blackfly]

Couldn't you spray it? You would have the whole canoe done in 5min, and then another coat the next day.

 

[Alan Gage]

I've got spray equipment but I don't have any sort of ventilation setup in my shop. I've sprayed smaller things in the shop without ventilation and even those leave quite a haze; and that was with a quick drying water borne finish where the mist is dry when it lands. I'd be afraid a slower drying varnish would leave a sticky film over everything in the shop.

Alan