Varnish Question

[Max Simmons]

Over the weekend I decided to do a little touch up on the caps and rails. There is also a mid-hull rub rail which had been raw over the last few years. It was originally varnished when I bought the boat 10 years ago, but I thought it would make better sense to just sand it down and let it go natural. I think that was about 5 yrs ago. Fast forward to Saturday and I decide it looked better varnished.
I removed the stainless steel trim and start sanding. It cleans up pretty nice and after a day of prep, I lay down the first coat of varnish, Petit Marine varnish, which I have had good results in the past. This teak is turning a much darker color than the rails and caps. My guess is that because the wood was in raw form over the last 5 years it is taking the varnish much differently than if I had re-done it way back when. The attached pic shows it (it's the lower one) before I applied varnish.
So, the question is should I have prepped this rail differently? Maybe a teak cleaner first?

 

[Delfin]

Over the weekend I decided to do a little touch up on the caps and rails. There is also a mid-hull rub rail which had been raw over the last few years. It was originally varnished when I bought the boat 10 years ago, but I thought it would make better sense to just sand it down and let it go natural. I think that was about 5 yrs ago. Fast forward to Saturday and I decide it looked better varnished.
I removed the stainless steel trim and start sanding. It cleans up pretty nice and after a day of prep, I lay down the first coat of varnish, Petit Marine varnish, which I have had good results in the past. This teak is turning a much darker color than the rails and caps. My guess is that because the wood was in raw form over the last 5 years it is taking the varnish much differently than if I had re-done it way back when. The attached pic shows it (it's the lower one) before I applied varnish.
So, the question is should I have prepped this rail differently? Maybe a teak cleaner first?

The issue is that the older wood has lightened up, so the comparison with newly sanded wood is noticeable. Not much you can do about that except strip everything and start over. One pro tip you might consider at some point in the future is applying epoxy to the wood after it is completely stripped. This tends to solve a lot of varnish problems because the varnish is over a much harder, more stable surface than applied directly to wood. I did a spruce mast that way and 8 coats of varnish lasted over 4 years before another coat was needed.

 

[GoneFarrell]

Delfin's advice is good. I did this on a small boat bright finished. I cut the epoxy 50/50 with acetone, flows into the grain better.

 

[Nomad Willy]

I'm not keen on epoxy. Admittedly it works well if you want to seal from the outside. Epoxy does work well at that. But any water or even moisture will be trapped behind the epoxy barrier. Many do this because it's popular and people assume because it's popular it must be good. Wood that breaths well will have much less moisture buildup.

I like to pre-coat wood w a mixture of turpentine, kerosene, varnish and oil. The oil being linseed oil. I use raw linseed oil if I'm going for a deep penetration pre-coat. I frequently use/mix small amounts so I can vary the porportions of oil and vehicle. After I get as much oil into the wood as possible I reach the crossroads whereas I need to decide if I want a soft/satin look or glossy finish. If bright and glossy is chosen I apply 3 to 8 coats of varnish. I prefer softer "high oil" varnish over the harder high resin low oil varnish.

if I decide to keep the finish w/o build I reduce the percentage of varnish and oil (oil much less so) and continue the applications as needed frequently on boat trips .. wiping away the excess oil, turp and kerosene (if used). This soft oil Finnish should be repeated every month or so. That's what I did in Alaska but in dryer climates much longer re-coat frequencies would prevail. And very long re-coat times prevail in the boat's interior.

 

[Maerin]

Delfin's advice is good. I did this on a small boat bright finished. I cut the epoxy 50/50 with acetone, flows into the grain better.

CPES by Smith & Co. works better yet, it's formulated to work with wood, is the consistency of diesel fuel and mixes in equal parts. Thinning epoxy to 50% with acetone interferes with the curing, so it never really hardens up. Using CPES on bare wood provides a great base, and if the 1st coat of varnish is applied while the CPES is still curing, it creates a chemical bond between the CPES and the varnish.

You can actually use muliple coats of CPES to build, as long as there's varnish over top to protect it as it has no UV inhibitors.

Spot varnishing is nearly impossible to do without creating shade differences, particularly if you go to wood. Eventually, it will even out, but it may take a year or more, depending on UV exposure. The only route to an even finish is to wood it all, and start from there, but that's a LOT of effort, particularly aggravating if most of it's still in good repair.

A spectacular varnish job is testament to a whole lot of prep work and a whole lot more careful application. There just aren't any shortcuts to excellent varnish work.

 

[Giggitoni]

This ^

 

[GoneFarrell]

Thanks for the tip mae. I had no hardening Issues with the job I did, still looks good, and I did that one in '93. I'll check out the cpes too.

 

[sean9c]

Problem with epoxy is lousy UV resistance. No problem under UV resistant varnish but then if you let your varnish go the epoxy breaks down with the UV goes all milky and ugly. Now you're trying to strip epoxy. Skip the epoxy and skip the CPES. If you want a sealer coat just thin down the first coat of varnish.

 

[Delfin]

CPES by Smith & Co. works better yet, it's formulated to work with wood, is the consistency of diesel fuel and mixes in equal parts. Thinning epoxy to 50% with acetone interferes with the curing, so it never really hardens up. Using CPES on bare wood provides a great base, and if the 1st coat of varnish is applied while the CPES is still curing, it creates a chemical bond between the CPES and the varnish.

You can actually use muliple coats of CPES to build, as long as there's varnish over top to protect it as it has no UV inhibitors.

Spot varnishing is nearly impossible to do without creating shade differences, particularly if you go to wood. Eventually, it will even out, but it may take a year or more, depending on UV exposure. The only route to an even finish is to wood it all, and start from there, but that's a LOT of effort, particularly aggravating if most of it's still in good repair.

A spectacular varnish job is testament to a whole lot of prep work and a whole lot more careful application. There just aren't any shortcuts to excellent varnish work.

I looked at the MSDS for CPES and it just uses MEK as the thinner, which is what I use to thin epoxy as a first coat that penetrates well. If the price is the same, use CPES, if not, you can make your own.

 

[Delfin]

Problem with epoxy is lousy UV resistance. No problem under UV resistant varnish but then if you let your varnish go the epoxy breaks down with the UV goes all milky and ugly. Now you're trying to strip epoxy. Skip the epoxy and skip the CPES. If you want a sealer coat just thin down the first coat of varnish.

You are quite right. Left in the sun without protective coating epoxy turns milky. But then again, without protective coating woods oxidize away, crack and look like hell. The point of epoxy is to harden the wood, seal out moisture, and provide a stable base for top coating. If you ignore maintaining the topcoat, you may have to remove the epoxy, which is no more difficult than any other sanding project. Having maintained boat wood for a very long time, given the choice between futzing around with strippers, then sanding and skipping the strippers and go straight to sanding, I'll go with a DeWalt orbital and 60 grit, then 180, then begin again.

Wood that "breathes" is wood that inhales as well as exhales, meaning you should get used to a much higher level of maintenance to keep the wood looking decent if you are averse to epoxy.

 

[C lectric]

Max, \
Are you positive the rub rail you are asking about is teak?

Not all rub rails are teak. Mine are gumwood, eucalyptus I believe, and its natural colour is much darker than teak. Looks good although for that piece I use Cetol Natural teak covered with the Cetol Gloss.

My boat was built locally , well 80 miles away, but gumwood was not uncommon as it is TOUGHer and HARDer than teak so stands up better where it may get banged into a dock.

I did lighten my gumwood up by using a light colour wood filler. I would not do that again though. I like that dark wood.

 

[Simi 60]

I looked at the MSDS for CPES and it just uses MEK as the thinner, which is what I use to thin epoxy as a first coat that penetrates well. If the price is the same, use CPES, if not, you can make your own.

Exactly, its a bloody ripoff for the miniscule amount of epoxy you get.

Try mixing a batch on a hot windy day and see how fast your dollars evaporate away on the wind.

For me and many others, metho s a better product to thin epoxy with.
Better for you as well, or at least, not as bad.

 

[DHeckrotte]

Wood changes color with sun exposure; which direction depends upon the species. Usually darker, usually browner; Teak gets lighter and yellower. True even under finishes.

Finishes change color with sun exposure; how depends upon the finish. Often 'mellow' or 'yellow', sometimes simply darker.

Give it some time in sunlight; I'd bet that the differences disappear.

Besides sunlight and UV degradation, finishes fail at points of water intrusion: cracks, joints, bedded edges. No surface treatments will stop that problem. Were you to remove and totally coat out the wood pieces with epoxy then water will be much less likely to get into the wood. Ditto coating out the wood with other finishes before installation/bedding etc. Reason is that epoxy is far less permeable than most finishes. However, epoxy has poor resistance to UV and must be coated with UV resistant finish.

I've taken to filling holes in wood with epoxy thickened with wood-based fillers. (Ex: West System resin and hardener with their 'Filleting Blend' filler.) I noticed that, on our previous boat, holes so filled survived under finishes. I reasoned that the filler impeded the UV from penetrating into the epoxy. A PO of our current boat filled some bung holes in our Teak decking with a similar substance. That filler now 'stands proud' of the rest of the wearing Teak. Similarly, I've taken to using the same filled epoxy for bonding wood on various parts of the boat with the expectation that the very narrow glueline will survive exposure.

I'm stripping the remains of failed finishes from all exterior Teak and we like the lovely grey.

 

[SoWhat]

Teak cleaners are not kind to teak wood. Can't beat 80/120/220 grit sanding. Clean with tack cloth then toluene. Thin out the first few coats. Start w/ 50%, 25%, 10% matte. Full strength matte for a few coats. Hard gloss for a few coats. Sand the gloss w/ 220 between coats. I used Epifanes and restored the original teak color.

 

[mike66]

This is the best solution. Really, go boating and I'm sure no one but you will notice the shade difference.

 

[Nomad Willy]

Re So What's post ..

Can't say it often enough .. teak cleaners are not kind to teak.

 

[Simi 60]

Teak cleaners are not kind to teak wood. Can't beat 80/120/220 grit sanding. Clean with tack cloth then toluene. Thin out the first few coats. Start w/ 50%, 25%, 10% matte. Full strength matte for a few coats. Hard gloss for a few coats. Sand the gloss w/ 220 between coats. I used Epifanes and restored the original teak color.

I'm guessing you spend a lot of time sanding and varnishing and not much time using the boat.

Me, I sanded all that varnished shite off with 60 grit on the two speed sander and gave it all a good drink of self priming exterior acrylic colour matched to close to original timber colour.
4 lots of rails done on a 60fter in a day.

Looks 1000% than the flaking mess that was there, see you again in several years.

 

[Simi 60]

This is the best solution. Really, go boating and I'm sure no one but you will notice the shade difference.

This ^^^