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View Full Version : After Painting, how about waxing ?



RodB
05-29-2004, 08:38 PM
There have been many postings on painting on this forum but I can't remember reading if anyone has ever brought up waxing the finished paint job after it has cured for a few months.

Is is a good idea (or great idea) or not to apply a quality wax over the paint job once it has dried completely just like automobiles?

If waxing is a good idea what is recommended for application on "Kirbys" alkyd enamels for instance ( Kirbys with the non-glossy finish)?

Just wondered,

RB

NormMessinger
05-29-2004, 09:02 PM
Wait until the paint it totally cures. The auto paint people say six weeks but I have not guess about boat paint.

If you ever plan to repaint do not let any silicon type waxes near your boat.

Otherwise go for it.

imported_Conrad
05-29-2004, 09:31 PM
It can be a good idea, especially for paints applied over glass/epoxy substrates. All paints except 100% solids epoxies are a bit porous. How much so depends on the type and formulation. As a general rule, the more thinner is used, the more porous the surface, since as the reducers evaporate they leave little worm-hole like passages in the paint. These passages expose more surface area to the atmosphere, and specifically oxygen, which promotes oxidation and paint breakdown. Water vapor can also make its way into/out of these pores, wetting and drying the wood underneath.

Traditional enamels are among the most porous with the new acrylics the least. All will increase in durability when waxed, as the wax seals/fills the pores and slows oxidation as well as the damage done by freezing/heated water vapor.

Basic carnuba wax works well for s short summer season while the "new polymer technology" can last all year. Silicon is very durable, but as Norm says, will make it very difficult to prep for a fresh paint job if less than a year has gone by.

Try to wax when the boat is dry to minimize trapping moisture under the finish, and expect two coats to really to it right.

Wild Wassa
05-29-2004, 10:17 PM
When my friend Frank the boat builder, came to see my new boat (I call her new), the first thing he said after seeing her was, "they go faster if you put coffin oil on them," ... :eek: . In the olden days, Frank raced the same class of boat, and rowed around in wood, ... so I forgive him.

I'm not sure if it was a laminar, non-laminar flow thing with Frank, but I felt he was not endorsing my new slippery purchase. Coffin oil?

Is the wax you use suitable for the marine environment? The hull buff liquid that I use isn't. It is a buffing medium not a permanent wax.

Warren.

ps, Dislexic boat painters of the world untie.

[ 05-29-2004, 11:42 PM: Message edited by: Wild Wassa ]

imported_Conrad
05-29-2004, 10:45 PM
Yeah, most buffing compounds are built around a light oil base- not the same thing. Some of the automotive glazes have resin fillers, sort of like wax, but not very durable.

The silicon based automotive "waxes" are the best- but make sure you're happy with the paint before applying. The only way to really get it off is gas or naphtha with a scotch-brite pad! :eek: :D

capt jake
05-29-2004, 11:50 PM
Interstesting; I was told that if you wax a hull, it will cause small bubbles to form as the water attempts to bead off of the finish. This beading (cavitation?) will cause addded drag, thus reducing the overall speed of the hull.

Was I fed something that I shouldn't have?? Or is it better to protect the finish with a wax or such (as I am still tempted to say is right, wax that is). ????

[ 05-30-2004, 01:12 AM: Message edited by: capt jake ]

Wild Wassa
05-30-2004, 12:27 AM
Originally posted by capt jake:
"This beading (cavitation?) will cause addded drag, thus reducing the overall speed of the hull."

This point is ponderred a lot in my boat shed. When I was working full-tine for the ACT Sea Scouts, my boss Garry Lymbury, would say, "... too smooth is too sticky."

Then I would say, "but Larson and Eliesson say in their book, 'The Principles of Yacht Design', glass-like is a surface that is closer to a realization of maximum hull speed." Garry says, "bubbles give lift." He and I remain at odds.

Warren.

[ 05-30-2004, 01:30 AM: Message edited by: Wild Wassa ]

imported_Conrad
05-30-2004, 01:22 AM
If the water is to remain in contact with the hull, ala traditional sailing craft, the smoothest surface is best, although the benefits of a surface smoother than what you get with about 800 grit paper shows little gain- the curve goes flat.

But water is denser and has more drag than air- hence, it's easier to push an object, like a boat, through air than it is water. The result is the new emphasis on stepped or ventilated hulls that pull air down through vents or channels and release it under the running surface along the hull of the boat, reducing the friction drag on the hull surface. It also breaks the suction hold that develops with certain hull shapes at speed.

A middle step is to use a soap-like substance on the hull to alter the flow characteristics of the laminar or closest layer of water against the hull. Or, alternately, modify the surface, like dimples do to a golf ball, to change the characteristics of the laminar flow, reducing drag. Shark's skin, and a few other fishes use this approach to reduce drag and allow them to swim faster for a given energy expenditure.

Simple, huh? :D :rolleyes: At this time the consensus for average sailors without access to top secret chemical compounds seems to be get the bottom as smooth and fair as possible. To the extent wax fills imperfections and smooths the bottom it probably helps. Whether it has a particular positive/negative interaction with the laminar flow and resulting drag potential I don't know. My guess would be a little cavitation would help break the water's hold on the hull....but to initiate cavitation requires some energy, so....??? tongue.gif smile.gif

RodB
05-30-2004, 02:10 AM
I am mainly talking about topsides and decks, consoles, etc. not the bottom.

I am planning on using Kirby's Alkyd enamel and I have plenty of the good old McGuires Carnuba wax on hand. I guess I'll just let it dry for a few months in our hot Texas weather and apply the old Mcguires... I haven't seen any other wax recommended as much as Mcguires for autos.

RB

Todd Bradshaw
05-30-2004, 02:26 AM
Keep in mind though, that the difference in speed resulting from any of these finishes is quite small as far as most recreational boats and boaters are concerned. Unless you're class racing with nearly identical boats and skipper skill levels you would probably never notice a difference at all.

I kind of like the 3M "One-Step" stuff. It's a wax containing a little bit of polishing compound. New enamel and new varnish tend to feel almost sticky and nearly always seem to have at least a few tiny bumps from dust, etc. This stuff polishes them out and leaves a nice, silky surface.

I'll echo Norm's warning about silicone on anything you might ever want to re-paint. I once sanded a thick coat of butt-ugly, curb-yellow Easypoxy enamel of of a 22' fiberglass hull that a friend had bought used. The paint had been treated with Starbright or similar polish containing silicone. I ground the paint off with the big disk and went down well into the original gelcoat to get a decent surface for the new paint. After some wet-sanding, it then got a healthy wipe-down with solvent and we had it sprayed. The new paint still fish-eyed like crazy. I haven't used anything claiming to contain silicone on a boat since.

Concordia..41
05-30-2004, 06:53 AM
From paint care do's and don'ts on Awlgrip's website:


1. Do not use traditional waxes. General: Traditional waxes break down rapidly. The residue can cause the topcoat to appear yellow, plus it attracts dirt. This creates the need to maintain the wax, increasing overall maintenance. Traditional waxes which contain no abrasives probably do little harm to the coating, but offer no benefit.

Awlgrip has developed AWLCARE™ Protective Polymer Sealer (73240) for those who want to enhance their finish and need the additional cleaning power of a hand applied, dry wash product. AWLCARE™ is a non-yellowing sealer that will protect both AWLGRIP® and AWLCRAFT® 2000 with regular applications. Hand applied AWLCARE™ will not harm Awlgrip’s topcoats and can easily be removed with AWL-PREP® PLUS-T0115 (or T0340 Surface Cleaner in Europe) when it is time to repaint.

The above sounds a bit like a press release, but I absolutely love their polymer sealer. And I wouldn't hesitate to try it on regular paint.

Full Text on Awgrip care (http://www.awlgrip.com/pages/auxill.html)

Scott Rosen
05-31-2004, 06:54 PM
I think waxing a traditional enamel like Kirby's is a bad idea.

First off, if you're using Kirby's, then you you're not looking for a super blinding gloss. You want a traditional, hard sheen, not a waxed look.

Second, it takes about as much effort to properly wax a hull as it takes to sand and put on a fresh topcoat. So why bother with the wax. A high-quality and durable enamel like Kirby's should look great for at least two years with proper care. When it starts to look a little shabby, sand off the oxidized surface and apply a new topcoat.

RodB
06-01-2004, 02:40 AM
Thanks Scott, I just thought that waxing would protect the paint job like on a car and I didn't think about it changing the gloss of the finish. If waxing doesn't offer any protection and longevity then your suggestion seems best. I also plan to keep my 20 foot skiff covered to maximize the life of my paint job.

thanks,

RB