Boat surface is chalky- What should I do

brianvolt7

Chief Petty Officer
Joined
Jun 7, 2008
Messages
423
I have buffed out my boat with a good rubbing compound and the chalkiness went away for a little while but now its back. Buffing and pressure washing have not done anything to solve the problem. Are there any recommendations to remove this layer of chalkiness permanently and leave a nice shiny appearance?
 

TojosMojo

Petty Officer 2nd Class
Joined
Aug 13, 2009
Messages
128
Re: Boat surface is chalky- What should I do

Since you did not mention it, I have to assume you did not final polish or wax the boat immediately afterward. As soon as you are done buffing with the compound you must come right behind it with a really good finishing polish, and as the finish is exposed you must then come behind that with a good wax for protection and shine ( the wax is the actual product that will protect the finish from oxidation again, plus it gives you the deep level shine you desire).

Basic 3 step process...

1: Compound - for oxidation and dullness, removes large amounts of surface damage
2: Polish - makes surface shiny again by removing small amounts of the top layer and smoothing out minor imperfections to create a deep shine.
3: Wax - protects and seals the finish and creates an even greater depth of shine...

Without step 3 you will get the oxidation back very quickly...Wax is the key, "Wax on... Wax off" then watch the sun bounce off it and the water bead... Step 4: enjoy the shine.
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: Boat surface is chalky- What should I do

Many compounds have oils in them, this is part of what brings back the gloss easily, the problem is its only a short term fix. If you don't remove all of the oxidized surface then as the oils go away the gloss is reduced and that dull colored surface comes back. For it to last you need to remove all of that oxidiztion, this may mean using a coarse compound or wet sanding, it just depends on the gel coat's condition.

You may want to read the Vasiline thread.
 

brianvolt7

Chief Petty Officer
Joined
Jun 7, 2008
Messages
423
Re: Boat surface is chalky- What should I do

Thanks to all for the advice and thanks for turning me onto the ENTERTAINING Vaseline thread.:p
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: Boat surface is chalky- What should I do

I've thought about this a while now,talked to an engineer freind and he gave his thoughts on it. Kinda has the ring of truth to it.

It will never last the way a fresh gelcoat looks straight from the mold.
When molded the microscopic structure of the gelcoat forms laterally against the surface of the mold, imagine it as long crystals which all lay flat against the mold. But if you take a section of molded gelcoat and snap it in half the exposed edge is not shiny. Because the internal structure is more like glass mat under a microscope.( or straw)

Thats why its very smooth and shiny when unmolded even without any wax on it. Its the same for anything molded, plastic, chocolate etc.
Snap a bar of chocolate, the surface is shiny from the mold, the inside is dull, capillary action aligns the crystals with the surface of the mold.

As that outter layer ages and turns to ash you get what looks like chalk.
Photoelectric effect causes it, photons hit the surface and carry away electrons from the atoms in the gelcoat, atoms disintegrate and molecules collapse , ash is the result.

And if you cut into it with compounds you get to a new level of gel but because it was free floating and not in contact with the mold the crystals are free floating and you actually cut into the crystals exposing their inner structure to the elements. They look fine for a while but soon break down.
Light is defracted by their haphazard arrangement and scattered rather than reflected , wax wears off and its dull again.

Vaseline simply polarizes the light and stops it from scattering.
 

brianvolt7

Chief Petty Officer
Joined
Jun 7, 2008
Messages
423
Re: Boat surface is chalky- What should I do

So it seems there is no way to permanently remove the chalk. I will follow the steps above because I have never waxed the boat.
 

allpoints360

Petty Officer 1st Class
Joined
Jul 23, 2009
Messages
342
Re: Boat surface is chalky- What should I do

Wet sand with 400, 600, 1000, compound, polish, then wax. Lots of work, but will look new.

It will never last the way a fresh gelcoat looks straight from the mold.
When molded the microscopic structure of the gelcoat forms laterally against the surface of the mold, imagine it as long crystals which all lay flat against the mold. But if you take a section of molded gelcoat and snap it in half the exposed edge is not shiny. Because the internal structure is more like glass mat under a microscope.( or straw)

Thats why its very smooth and shiny when unmolded even without any wax on it. Its the same for anything molded, plastic, chocolate etc.
Snap a bar of chocolate, the surface is shiny from the mold, the inside is dull, capillary action aligns the crystals with the surface of the mold.

As that outter layer ages and turns to ash you get what looks like chalk.
Photoelectric effect causes it, photons hit the surface and carry away electrons from the atoms in the gelcoat, atoms disintegrate and molecules collapse , ash is the result.

And if you cut into it with compounds you get to a new level of gel but because it was free floating and not in contact with the mold the crystals are free floating and you actually cut into the crystals exposing their inner structure to the elements. They look fine for a while but soon break down.
Light is defracted by their haphazard arrangement and scattered rather than reflected , wax wears off and its dull again.

Not sure I understand this, or agree, Jonesg. I've sprayed gelcoat, sanded and polished with great results.
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: Boat surface is chalky- What should I do

I've thought about this a while now,talked to an engineer freind and he gave his thoughts on it. Kinda has the ring of truth to it.

It will never last the way a fresh gelcoat looks straight from the mold.
When molded the microscopic structure of the gelcoat forms laterally against the surface of the mold, imagine it as long crystals which all lay flat against the mold. But if you take a section of molded gelcoat and snap it in half the exposed edge is not shiny. Because the internal structure is more like glass mat under a microscope.( or straw)

Thats why its very smooth and shiny when unmolded even without any wax on it. Its the same for anything molded, plastic, chocolate etc.
Snap a bar of chocolate, the surface is shiny from the mold, the inside is dull, capillary action aligns the crystals with the surface of the mold.

As that outter layer ages and turns to ash you get what looks like chalk.
Photoelectric effect causes it, photons hit the surface and carry away electrons from the atoms in the gelcoat, atoms disintegrate and molecules collapse , ash is the result.

And if you cut into it with compounds you get to a new level of gel but because it was free floating and not in contact with the mold the crystals are free floating and you actually cut into the crystals exposing their inner structure to the elements. They look fine for a while but soon break down.
Light is defracted by their haphazard arrangement and scattered rather than reflected , wax wears off and its dull again.

Vaseline simply polarizes the light and stops it from scattering.




That's sort of accurate, it actually has more to do with the fillers and pigments though.

When gel coat is sprayed into the mold there is a very thin layer of resin rich gel coat at the mold surface which can be very glossy, when this layer is removed by any means (sun, sanding, buffing, wear, etc) you're left with exposed fillers and pigments. These fillers and pigments don't hold a shine like resin will, so typically the new surface won't stay glossy as long as an original one will. This also depends on the gel coat too, some are formulated for better buff back gloss and may do very well after being buffed.
 

navis

Seaman
Joined
Oct 18, 2008
Messages
68
Re: Boat surface is chalky- What should I do

Very interesting read. Wouldn't the wax fill in where the molecules have decayed, Creating a smooth shiny surface, until the wax wears off of course.

If you are talking about particle radiation, the boat would have to be extremely old to even be noticeably effected. Hold out your finger, millions of particles of radiation will pass through it, hurts don't it :p Buy a piece of a radioactive moderator, set it on the side of a brand new boat, it will never even effect it.

To answer your question, I have had pretty good luck with turtle wax (the good stuff in the green tub) as long as the surface is really well prepped. I have also heard of really good results with a product called "pollyglow" which we will be using on our boat once it's time.
 

brianvolt7

Chief Petty Officer
Joined
Jun 7, 2008
Messages
423
Re: Boat surface is chalky- What should I do

Thank goodness for Turtle Wax.

I was just about to look up Sunlight disbursement patterns, Global Warming, Cell Mitosis, Flux Capacitors, and the phone number to NASA. :)

Just kidding- thanks to all of you for your posts, I didn?t understand most of it but thanks!
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: Boat surface is chalky- What should I do

Very interesting read. Wouldn't the wax fill in where the molecules have decayed, Creating a smooth shiny surface, until the wax wears off of course.

If you are talking about particle radiation, the boat would have to be extremely old to even be noticeably effected. Hold out your finger, millions of particles of radiation will pass through it, hurts don't it :p Buy a piece of a radioactive moderator, set it on the side of a brand new boat, it will never even effect it.

To answer your question, I have had pretty good luck with turtle wax (the good stuff in the green tub) as long as the surface is really well prepped. I have also heard of really good results with a product called "pollyglow" which we will be using on our boat once it's time.

right, the wax fills in the rough surface but wax isn't hard as gelcoat and soon you're back to the same dullness.
Strong sunlight will tear most surfaces up after a few yrs.

New gelcoat, sprayed , sanded and polished looks about as good as molded but I don't think it will last quite as long, its still better than older sanded.

I used maguires machine polish on the insides of glass molds I made and they came out like mirrors, but that was new tooling gelcoat.

My hull is 1974 but still smooth and shiny, not clean though:D
I think I'll just let my old boat be what it is, an old boat.
I suspect if I start with the machine polish it will degrade all the faster.
 
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