<removed> see below </removed>
<removed>unless your boat was really expensive or you put it on yourself the gel coat on your boat is Polyester of some form, NOT epoxy. Epoxy is not UV stable and would need to be covered by something else, or chemically altered (expensive) to protect it from UV.
Do these ?shining agents? damage the polyester? Generally No. Once fully cured, unless you attack the polyester with a solvent, it will resist damage from most other chemicals. It is not inert however and will react. Oxidization is one such reaction. So be sure that the ?shining agent? is listed by the manufacturer as safe for use on polyester.
Is polyester impervious to chemical penetration? No. All polyester is porous to some extent. (So is epoxy.) This is where using a ?shining agent? can cause problems. When you apply a ?shining agent? it penetrates all the little surface scratches, pits, dips, and pores. This levels out the perceived surface of the gel coat and makes it ?shiny? until the ?shining agent? is either worn, washed, or degrades off. When the ?Shining agent? penetrates the pores, cracks, etc. some of it penetrates rather deeply and is not easily removed by washing or scrubbing and because it is now somewhat protected with limited exposure it may not degrade quickly. Most of it does and that is why you need to reapply it. It is the length of time that this takes that is usually indicative of the ?quality? of the shining agent. These ?shining agents? do not remove oxidization (damage) it only hides it.
The sanding/polishing method does the same thing only it attempts to make the surface smooth by removing the high spots until the perceived surface is level, and it is the re-introduction of the scratches and pitting that make the surface unlevel reducing the ?shine?. This method does remove the oxidized (damaged) layer which is why it generally last longer.
Back to our problem?
Vaseline is used as a barrier gel, sometimes called a barrier cream, which means that it does not allow things to penetrate through it. This includes glass-fiber dust, polyester dust, air, and the chemicals in polyester resin. Many ?shining agents? have some barrier qualities and actually repel chemicals (Substances that repel water are called hydrophobic). So, when you go to re-paint or re-gel coat the tiny amounts of the ?shining agents? still in the pits and pores do their job as a barrier and can repel the new surface you are trying to apply. This usually manifests itself as a ?fisheye? a spot where the resin or paint has been pushed away down to the old surface. (Now, I know there are lots of other reasons coatings fail but I am using this as an example of one way) It may be very expensive, require a harsh chemical solvent, or some mechanical (sanding/grinding) method to remove the contaminant.
So, when professionals say it is bad it is because they have experience with re-finishing and the problems that the ?shining agents? cause. They also have the experience, knowledge, facilities, and expertise that makes re-finishing easier for them than for most <edit>non professional boat restorers</edit>.
It should also be noted that because of the potential for more work later on, that when restoring a valuable collectable boat, by applying the ?shining agents? you may be damaging the value of the boat you are trying to restore.
For most of the <edit>non professional boat restorers</edit> who are just looking to improve the ?shininess? of their boats and are not working on a collectable boat where the value may be damaged then the ?shining agents? are a good alternative <edit> and work perfectly acceptably</edit> They just need to be aware that in the future they may be setting themselves up for more expense and work.
<removed>paint jobs that look deep and are really reflective are accomplished with layers (10 or more in some cases) of clear coat and hours of polishing, not waxing. <removed>see below</removed>
<removed>unless your boat was really expensive or you put it on yourself the gel coat on your boat is Polyester of some form, NOT epoxy. Epoxy is not UV stable and would need to be covered by something else, or chemically altered (expensive) to protect it from UV.
Do these ?shining agents? damage the polyester? Generally No. Once fully cured, unless you attack the polyester with a solvent, it will resist damage from most other chemicals. It is not inert however and will react. Oxidization is one such reaction. So be sure that the ?shining agent? is listed by the manufacturer as safe for use on polyester.
Is polyester impervious to chemical penetration? No. All polyester is porous to some extent. (So is epoxy.) This is where using a ?shining agent? can cause problems. When you apply a ?shining agent? it penetrates all the little surface scratches, pits, dips, and pores. This levels out the perceived surface of the gel coat and makes it ?shiny? until the ?shining agent? is either worn, washed, or degrades off. When the ?Shining agent? penetrates the pores, cracks, etc. some of it penetrates rather deeply and is not easily removed by washing or scrubbing and because it is now somewhat protected with limited exposure it may not degrade quickly. Most of it does and that is why you need to reapply it. It is the length of time that this takes that is usually indicative of the ?quality? of the shining agent. These ?shining agents? do not remove oxidization (damage) it only hides it.
The sanding/polishing method does the same thing only it attempts to make the surface smooth by removing the high spots until the perceived surface is level, and it is the re-introduction of the scratches and pitting that make the surface unlevel reducing the ?shine?. This method does remove the oxidized (damaged) layer which is why it generally last longer.
Back to our problem?
Vaseline is used as a barrier gel, sometimes called a barrier cream, which means that it does not allow things to penetrate through it. This includes glass-fiber dust, polyester dust, air, and the chemicals in polyester resin. Many ?shining agents? have some barrier qualities and actually repel chemicals (Substances that repel water are called hydrophobic). So, when you go to re-paint or re-gel coat the tiny amounts of the ?shining agents? still in the pits and pores do their job as a barrier and can repel the new surface you are trying to apply. This usually manifests itself as a ?fisheye? a spot where the resin or paint has been pushed away down to the old surface. (Now, I know there are lots of other reasons coatings fail but I am using this as an example of one way) It may be very expensive, require a harsh chemical solvent, or some mechanical (sanding/grinding) method to remove the contaminant.
So, when professionals say it is bad it is because they have experience with re-finishing and the problems that the ?shining agents? cause. They also have the experience, knowledge, facilities, and expertise that makes re-finishing easier for them than for most <edit>non professional boat restorers</edit>.
It should also be noted that because of the potential for more work later on, that when restoring a valuable collectable boat, by applying the ?shining agents? you may be damaging the value of the boat you are trying to restore.
For most of the <edit>non professional boat restorers</edit> who are just looking to improve the ?shininess? of their boats and are not working on a collectable boat where the value may be damaged then the ?shining agents? are a good alternative <edit> and work perfectly acceptably</edit> They just need to be aware that in the future they may be setting themselves up for more expense and work.
<removed>paint jobs that look deep and are really reflective are accomplished with layers (10 or more in some cases) of clear coat and hours of polishing, not waxing. <removed>see below</removed>
