Best way to strip 2-pack marine varnish?

[strangerep]

OK, so I'm totally over the whole thing about having a beautifully finished timber handrail on my (fully exposed) balcony...

It was finished with endless coats of International's "Perfection" 2-pack marine varnish (with Everdure 2-pack sealer underneath). Looked absolutely stunning for a several years, but now I can pull off whole strips of it starting at the ends -- like cheap sticky tape .

The timber underneath is still sound, so I'd like to strip off the remaining varnish (from the underside of the handrail and other places where it doesn't yet peel off easily), and repaint it (this time with ordinary paint which lasts much longer and is much easier to maintain).

The handrail has a elliptical profile, so the curved surface prevents use of a belt sander -- any low-grit sanding needs to be done by hand, which I can't face.

Can I just use an ordinary paint stripper? Or does 2-pack varnish need something special to remove it thoroughly? Will a heat gun work successfully on 2-pack? If so, what temperature?

TIA for any advice!

[Oddjob1]

Polystripper is ok for that but messy, perhaps try the heatgun, hot!

Oddjob1 Good luck!

[Bernt]

On boats I always used a scraper, no paintstipper or anything. Sad to hear you have to go for paint... On wooden parts on boats I usually lightly sand and recoat every year or two, that seems to keep it nice. Often when people skip a year or two with maintainance you are too late and have to go back to bare wood. How long did you get out of your varnish?

I feel your pain about the sanding, I just spend 2 days sanding profiled handrail by hand.

Good luck!

[Heilander]

On boats I always used a scraper, no paintstipper or anything. Sad to hear you have to go for paint... On wooden parts on boats I usually lightly sand and recoat every year or two, that seems to keep it nice. Often when people skip a year or two with maintainance you are too late and have to go back to bare wood. How long did you get out of your varnish?

I feel your pain about the sanding, I just spend 2 days sanding profiled handrail by hand.

Good luck!

Agreed I do the same for my verandah rails and steps using spar marine varnish, get's about a couple of years (I live in Mackay) but worth it to see the beautiful grain.IMHO oh,and broken glass shards make good scrapers

Scotty

[strangerep]

Polystripper is ok for that but messy, perhaps try the heatgun, hot!

Thanks. I had a feeling that would be the case.

I must weigh up the time and frustration of stripping 11m of this stuff versus the cost of simply having some replacement rails re-milled -- for which I won't get much change out of $1,000.

On boats I always used a scraper, no paintstripper or anything. Sad to hear you have to go for paint... On wooden parts on boats I usually lightly sand and recoat every year or two, that seems to keep it nice. Often when people skip a year or two with maintainance you are too late and have to go back to bare wood.

Re-coating in my situation is very difficult since the balcony is high. I.e., I can get easy access only from one side. So I had to try and mask the other side and then carefully lean over with roller and foam brush... There's no way I could tolerate all that fuss -- nor survive the severe stress on my lower back muscles -- very often.

Also, I have yet to install a further 18m of the same handrail...
So eventually I must either maintain almost 30m of difficult-access handrail every year or two, or go back to paint.

How long did you get out of your varnish?

4 years for the initial coat (which astounded one of the guys at Whitworths), but then only 2 years for the second coat.

But actually it's more complex than that. I applied the initial coat before installation, so I was able to coat the end grain of mitred sections really thoroughly. But I made the mistake of filling in between these sections with an acryllic colour-matching caulk. (It said "exterior" on the tube, but that was before I knew that such claims are absolute rubbish.) So gradually the rain re-emulsified the acryllic caulk and now almost all of has washed away. This had the consequence that I couldn't recoat the end-grain of the sections properly -- and most of the peeling has started from these points.

There were also a couple of points where the new coat started bubbling from the top very quickly. I guess this was due to not sanding back enough, or maybe moisture on the surface? In fact, therein lies another dilemma: since it's fully-exposed I had to pick cloudy days in winter to do the recoats and hoped for the best. But days are very short in winter and the evening dew develops quickly. So even though I recoated in the morning maybe there wasn't enough time for the varnish to cure sufficiently to be resilient against overnight dew?

In any case, I now understand that re-varnishing with 2-pack is actually much more difficult (to do successfully) than the initial coat.

I feel your pain about the sanding, I just spend 2 days sanding profiled handrail by hand.

Only 2 days? How many metres of handrail was that?

[Bernt]

One other aspect about some 2 pack lacker is that they don't easily recoat once they have fully cured. A single pack boat varnish might be more suitable to quickly sand and recoat every spring.

You are right about the exterior grade products, for things like that you have to go marine grade.

Could you make the handrail so it is easily removable? Might be handy for your refinish now but makes it easier in the future too. Also paint needs upkeep. (really not that different)

[strangerep]

One other aspect about some 2 pack lacker is that they don't easily recoat once they have fully cured. A single pack boat varnish might be more suitable to quickly sand and recoat every spring.

I considered that 6 years ago when I started. But there is far too much work (still) to be done on my house (i.e., renovating most of the interior). I thought the 2-pack would last longer than it did.

Could you make the handrail so it is easily removable?

It is already fixed onto angle aluminium by screws from underneath. But the problem is the mitred joins between sections. They need some kind of flexible filler such a Sikaflex. Even though the mitre angles and lengths were almost perfect when first installed, timber inevitably expands and shrinks outside, no matter how good the coating. So I'd have to cut the Sikaflex out at each removal and then re-do it upon installation. Not really practical.

Also paint needs upkeep. (really not that different)

I agree paint needs upkeep, but I'm pretty sure it will last longer than 6 years before needing a major recoat. It's also more forgiving if you need to touch it up in places.

I plan to apply many coats of oil-based primer/undercoat until the grain is entirely filled, then 3-4 coats of Endure gloss. The only uncertainty I have concerns the failure modes of Endure. I'm very familiar with how Weathershield ages, and powders up, etc, but Endure might be a bit different since it's a tougher surface. Dunno.