Polishing gelcoat makes it go dull - what am I doing wrong?

[Totts]

Polishing gelcoat makes it go dull - what am I doing wrong?




I'm fairly new to polishing boats and hit upon a curios problem. I'm hoping that some of your experience might throw some light onto what I'm doing wrong.

I've been using a Makita rotary with a heavy wool pad and Presta Super Cut Compound and parts of the boat have come up beautiful. In fact, it looks like it doesn't need any further work but I'm aware that you'd probably see swirl marks under certain light, so I thought it would be best to finish off with some light polishing.

For this I've used a Makita DA (Orbital) with a Lake Country soft green and blue polishing pads and Presta Ultra Polish. This is where the problem starts...

instead of increasing the depth of shine, it's doing the complete opposite, in some areas, it has made the gelcoat completely dull so there was no reflection at all and giving a frosted appearance.

In order to remedy this I've got the Rotary and compound out again, even so, that hasn't brought it back up to where it was originally.

I first noticed it when the Oribital was in "forced rotation" mode and I thought that perhaps I'd scorched the gelcoat so I repaired what I'd done then tried it in "Free spinning" mode but it did the same thing, though not quite so bad so there could be a clue there.

It hasn't happened on all areas, some parts are fantastic, no swirl marks and mirror like finish, so I'm pretty confused about what's causing it. I've stopped using the Oribtal now until I can figure out what's going on.


These are the things I'm thinking...

• am I using too much polish and everything got clogged, but why would that make the gelcoat unreflective and frosted looking? Also the foam pads were fresh on and I'd only been using them for a few minutes.
• is the dual action orbital speed too high/low? I used around 3000 OPM.
• I'm in South Florida, so I've even questioned whether the humidity was causing problems. I've noticed that when it's humid, it can be quite hard to polish off residual polish with a microfibre cloth.
• I don't think the pads were too hard since they're good pads and designed for light polishing (blue/green Lake Country flat pads).
• was I putting too much pressure on the orbital in forced rotation mode and it burned/damaged the gelcoat, so I switched to free spinning and it did the same thing, but not quite so bad.

If someone would be kind enough to share the benefit of their experience, I'd very much appreciate it. I'd like to put that Orbital to good use.

 

[Dano shine]

I would try a blue finishing wool pad at 1400 on your rotary with Presta Ultra Polish. Do a test spot and see what happens.

 

[Totts]

Thank you Dano, perhaps I was going a bit fast with the Orbital. I had the impression that Orbitals were more forgiving than a Rotary. I'll look into the blue finishing wool pads, but I'm really interested in knowing what may have caused the Orbital to make the gelcoat go dull as I know these devices have a lot of potential and would like to use it. Thanks again

 

[Mike PhillipsMike Phillips is verified member.]

I'm fairly new to polishing boats and hit upon a curios problem. I'm hoping that some of your experience might throw some light onto what I'm doing wrong.

I've been using a Makita rotary with a heavy wool pad and Presta Super Cut Compound and parts of the boat have come up beautiful. In fact, it looks like it doesn't need any further work but I'm aware that you'd probably see swirl marks under certain light,

Correct.

Rotary polishers inflict holograms swirls. I think I'm the ONLY guy on Planet Earth that has an article on this topic.

Holograms in gel-coat boats by Mike Phillips

But... I'm not a YouTube Influencer so take anything I say or write with a grain of cyber salt. :dunno:

so I thought it would be best to finish off with some light polishing. For this I've used a Makita DA (Orbital) with a Lake Country soft green and blue polishing pads and Presta Ultra Polish.

This is where the problem starts... instead of increasing the depth of shine, it's doing the complete opposite, in some areas, it has made the gelcoat completely dull so there was no reflection at all and giving a frosted appearance.

You thought right but what you thought doesn't work. For some reasons, gel-coat does not like soft foam pads for polishing/abrading work. It dulls the gel-coat. I stated this somewhere in my book on boat detailing. I also stated that I didn't know WHY gel-coat reacts this way and went on to state the I've never met ANYONE that could explain why gel-coat acts this way. So it's a mystery.

Paperback book - How To Detail Boats With Marine 31 by Mike Phillips

What I use and teach in my boat detailing classes is for the polishing step - use the RUPES coarse blue foam pads. Here's my article on these pads from 2014 - 6 years ago.

Mind Blowing - Rupes Blue Foam Cutting Pad and Zephir Gloss Coarse Gel Compound

This one should fit your polisher. It will take more than one pad to polish your boat but I would just get one to test first. Another problem might be the Presta polish.

Rupes 150 mm (6 inch) Blue Coarse Foam Pad


I've never used Presta products but when I met and worked with a very FAMOUS TV star, all the cars at his famous shop were swirled out with holograms. The ONLY tool he owned was an old Black & Decker rotary buffer with a wool pad on it. The only products I saw in his shop were Presta. And every car they had buffed out looked like crap. So I would not blame Presta for the swirled-out cars I would first blame the wool pad on the rotary buffer. But - I've never used Presta products so I don't know first-hand if they use GREAT abrasive technology or CRAP for abrasive technology. I would have to test them to know.


Abrasive Technology - THE most important factor when it comes to polishing paint

 

[Totts]

Excellent reply Mike, thank you very much.

I went back to the boat yesterday armed with a hard, yellow, Lake Country foam pad, (it's their cutting version). I tried it in various places and near to where I experienced dulling/frosting with the soft polishing pads and I can confirm that I encountered no problems at all, so I think you've hit the nail firmly on the head!

I also did a pass over the part which was damaged with the soft pad and it markedly improved it. I think in order to fully remedy it, I'd probably need to wet sand.

I thought this was going to be one of those problems where it was going to re-occur and haunt me, so I'm very pleased to have an answer, however, I'd really like to know why it happens. As you said,


"I've never met ANYONE that could explain why gel-coat acts this way. So it's a mystery"!


In addition, the dulling was so bad (zero on a gloss meter bad) and not easily remedied, that I'd have thought this problem would be common knowledge. I've spent quite some time reviewing pads online and it hasn't come up at all.

If you have gems like this in your book, then I'd like to own a copy, however I can't find where to buy it. I even saw one link where it said it was discontinued! Is it still available please?

I'm also going to buy one of the blue Rupes pads to try, but now how 5 redundant Lake Country pads!

Thanks again for taking the time Mike, it's much appreciated.

 

[57Rambler]

For some reasons, gel-coat does not like soft foam pads for polishing/abrading work. It dulls the gel-coat.

Here's my theory.

Gel coat is very hard, but it is also very porous, esp. as it ages. If you use a soft foam pad that is not very aggressive, you mainly end up just smearing your polish/compound in to the pores of the gel coat rather than the intended effect of removing a thin outer layer of the gel coat (to expose less damaged material underneath). That polish/compound trapped in the pores of the gel coat thus creates the dull appearance.

I'll send you my bill ... :laughing:

 

[Mike PhillipsMike Phillips is verified member.]

Here's my theory.

Gel coat is very hard, but it is also very porous, esp. as it ages.

If you use a soft foam pad that is not very aggressive, you mainly end up just smearing your polish/compound in to the pores of the gel coat rather than the intended effect of removing a thin outer layer of the gel coat (to expose less damaged material underneath).

That polish/compound trapped in the pores of the gel coat thus creates the dull appearance.

I think that's a good theory and as good as any I've read, but I've buffed out a lot of gel-coat using a lot of different pads and while I think that could be the reason in some instances, I still stick by my theory that gel-coat i.e. pigmented polyester resin, polishes up to a harder more clear shine using a hard, sharp foam pad on an orbital polisher versus a soft foam pad.

Of course there are exceptions, I've never seen an issue with soft foam pads on gel-coat that already has a clear, hard shine for applying a non-cleaning wax or sealant. It only seems to be a factor when "abrading" by machine during the finishing step.

One other factor that I never see anyone talk about.

 

[Mike PhillipsMike Phillips is verified member.]

.

If you have gems like this in your book, then I'd like to own a copy, however I can't find where to buy it.

I even saw one link where it said it was discontinued!

Is it still available please?

Interesting? Usually when we're out of a product it's listed as,

Out of stock


I know we ran out of the first edition, but since the original publishing, more products, tools and pads have been introduced, so it, like all of my books,


1 The Complete Guide to a Show Car Shine
2 The RUPES BigFoot Paint Polishing System
3 How to use the FLEX XC 3401 VRG
4 How to Detail Boats with Marine 31




They all need to be updated.

 

[Mike PhillipsMike Phillips is verified member.]

Excellent reply Mike, thank you very much.

My work on this forum is just an extension of Autogeek's Customer Care. Most people think customer are is calling the 1-800 number, but this is just a version of it. The difference between a phone call and this forum is my content I create has the potential to endure forever and be read by tens of thousands of people.

I went back to the boat yesterday armed with a hard, yellow, Lake Country foam pad, (it's their cutting version). I tried it in various places and near to where I experienced dulling/frosting with the soft polishing pads and I can confirm that I encountered no problems at all, so I think you've hit the nail firmly on the head!

The Lake Country yellow foam is an aggressive foam BUT nothing I've seen to date comes as close as the RUPES coarse blue foam formula. The next closest thing would be the Griot's Garage white foam cutting pads.

I'm also going to buy one of the blue Rupes pads to try, but now how 5 redundant Lake Country pads!

Thanks again for taking the time Mike, it's much appreciated.

Contact me via e-mail when you place your order and I'll have Customer Care include a sample of the Captain's Compound. Test this against what you're using and let us know what you think.

 

[Markymapo1]

Just ordered 10 Rupes coarse blue pads to get boat ready for spring (as soon as the ice comes off the lake, which this year is very thin, some parts in the middle didn’t freeze thick). Read “How to Detail Boats listed above many times over. Great book.

 

[dnadrifterr]

So looks like it isn't available anymore? I would like a copy too.

Interesting? Usually when we're out of a product it's listed as,

Out of stock


I know we ran out of the first edition, but since the original publishing, more products, tools and pads have been introduced, so it, like all of my books,


1 The Complete Guide to a Show Car Shine
2 The RUPES BigFoot Paint Polishing System
3 How to use the FLEX XC 3401 VRG
4 How to Detail Boats with Marine 31




They all need to be updated.

 

[Totts]

I e-mailed Mike because the boat detailing one is missing from the above links and when you do find it elsewhere on this site, it says discontinued, so I can't actually find anywhere I can buy it from at the moment. Perhaps I haven't stumbled across the correct place, but in any case, they're probably missing out on sales

 

[dnadrifterr]

I e-mailed Mike because the boat detailing one is missing from the above links and when you do find it elsewhere on this site, it says discontinued, so I can't actually find anywhere I can buy it from at the moment. Perhaps I haven't stumbled across the correct place, but in any case, they're probably missing out on sales

I looked for awhile too and couldn’t find it. Got the same discontinued you did.

 

[Totts]

ha exactly, I get the feeling they weren't aware, hopefully they've fix it so it becomes available now

 

[Mike PhillipsMike Phillips is verified member.]

Just ordered 10 Rupes coarse blue pads to get boat ready for spring (as soon as the ice comes off the lake, which this year is very thin, some parts in the middle didn’t freeze thick).

Thank you for your business and this means thank you for your trust. :dblthumb2:

Read “How to Detail Boats listed above many times over.


Great book.

Thank you.

I wrote the majority of that book in 10 days, by this I mean I typed out all the text in 10 days. Management came to me and asked me how long it would take to write this book and I told them

As long as I'm not interrupted, I could probably write the book in 2 weeks"

And I did. BUT - unbeknownst to me at that time, Nick Rutter had been working on about 6 NEW Marine 31 products. Because of this, I had to,

1. First use the products.
2. Take pictures of the products.
3. Write new copy for the products.

This probably took another 2-3 weeks. People that don't "write" wouldn't understand what's involved.

Using products, taking pictures and writing copy, that is the REAL DEAL, not MOCK-UP is time consuming. Once the real-world hands-on experience is in my brain, I have no problem using a keyboard to teach someone how to use a product.

The boat book was the most DIFFICULT book I've ever written. Here's why,

I had to include ALL the major tools being sold by Autogeek AT THAT TIME in the book. PLUS share how to restore all 4 conditions of gel-coat boats by HAND. If I didn't cover every tool and how to work by hand, the book would be limited to only those people that owned the tools I showcased how to use.

Make sense?

That's why when you read the book you see dedicated sections for each tool on the market AT THAT TIME. Today as I write, Monday, March 2nd, 2020 - there's been a LOT of new tools introduced to the market that are not in the first edition of the book. The good news is, at this time, no new hands have been introduced to the market.


:laughing:

 

[Totts]

Following some northerly winds yesterday, the air quality was very good and with a bright sun, I had an opportunity to inspect the boat carefully. I could clearly see that the texture of the gelcoat had changed where I'd used a soft pad, it had become annealed. I suspect that for some reason, soft foam pads are scorching the contact with the gelcoat and the surface molecules are restructuring, hence why it is doesn't simply polish out, you're actually altering the nature of the gelcoat.

I also spent a bit more time with the Lake Country yellow cutting pad and though nowhere near as bad, it still caused some of this annealed texture and dulling.

I'd estimate that on the worst area, reflection went from around 90 GU's (showroom but with swirls) down to next to nothing, so if you were to hold a polish bottle next to it, you wouldn't see any reflection whatsoever.

I'll be trying the blue Rupes pad soon with some Captains Compound and I'll report back.

I note that although other people have had similar experiences to this whilst using foam pads on gelcoat, they have different degrees of severity, so I'm wondering whether this can change from boat to boat? Thats another question!

 

[Mike PhillipsMike Phillips is verified member.]

Following some northerly winds yesterday, the air quality was very good and with a bright sun, I had an opportunity to inspect the boat carefully. I could clearly see that the texture of the gelcoat had changed where I'd used a soft pad, it had become annealed. I suspect that for some reason, soft foam pads are scorching the contact with the gelcoat and the surface molecules are restructuring, hence why it is doesn't simply polish out, you're actually altering the nature of the gelcoat.

I also spent a bit more time with the Lake Country yellow cutting pad and though nowhere near as bad, it still caused some of this annealed texture and dulling.

I'd estimate that on the worst area, reflection went from around 90 GU's (showroom but with swirls) down to next to nothing, so if you were to hold a polish bottle next to it, you wouldn't see any reflection whatsoever.

Like I explained in my boat detailing book, when used for abrading the surface, soft foam pads or orbital polishers, (and probably rotary polishers too), just seem to DULL the finish. They'll take a hard shine created by a hard pad, by this I mean a traditional wool pad on a rotary buffer and dull it down.

I'll be trying the blue Rupes pad soon with some Captains Compound and I'll report back.

I passed off a mostly full quart bottle of the Captain's Compound to Customer Care to include in your order. I'll check in a few minutes to see if it made it into you box. If no, I'll simply ship it to you stand-alone.

I note that although other people have had similar experiences to this whilst using foam pads on gel-coat, they have different degrees of severity, so I'm wondering whether this can change from boat to boat?

Thats another question!

My best guess is the pigment "can" be a huge factor. All gel-coat stars out as polyester resin, I'm sure there are formula differences between manufactures, but at the core of the substance, it's polyester resin. This has a known hardness and buff-ability.

When you add a pigment, red, blue, yellow, white, black, etc., the pigments are all different in their hardness characteristics and my guess would also be in their buff-ability characteristics. And this could and would be a reason to see different colored gel-coat boats react differently to everything. Time induced oxidation, appearance longevity and yes, any sanding, compounding, polishing or when using one-step cleaner/waxes.

Me? I've seen red pigmented gel-coat be the worst for resisting oxidation and I've had a bunch of severely red boats here at Autogeek.


From this photo-documented thread,

Boat Detailing Training - Before & After Pictures - The MOST DOCUMENTED HANDS-ON Boat Detailing Classes - Autogeek - Stuart, Florida


From this boat detailing class


2016

Pictures and comments: Marine 31 Boat Detailing Class - February 6th, 2016

BEFORE

Ghosting
Graphics were removed by the owner, which left ghosting behind....

The Test spot includes,

1. Waterless wash
2. Machine sand
3. Machine compound
4. Machine polish
5. Chemically strip
6. Install Marine 31 Captain's UV50 Ceramic Coating

AFTER

But with the right products, pads, tools and techniques, red can be brought back to better than new appearance.




Hope that helps...

 

[Totts]

:updated:


I ordered a couple of blue Rupes cutting pads and Mike kindly sent some Captains Compound for me to try with them. Captains Compound is a one step compound and polish.

The blue Rupes pads are really quite course and stiff, more so than I was expecting and the Captains Compound was the opposite, that is to say, when rubbed between the fingers, its creamy with almost no discernible texture. I was expecting to feel some grittiness but then I guess Captains Compound isn't professing to be a heavy cut compound such as 3M's offering.

I waited for a sunny day so I could really see what was going on and tried the combination on two boats, one or which is gel-coat and the other has been painted.

As there's little flex in the Rupes pad, it does take a bit of getting used as they don't hug the surface like softer pads, however, the combination worked very well on both boats, which is cutting and polishing at the same time.

Under sunlight, I could see that the combination had worked well on the moderately oxidized surfaces and I couldn't see any swirl marks.

The holograms and fine scratches were removed nicely.

So in essence, the combination works well together, a successful result.

In addition, I didn't see any dulling/frosting with that annealed texture I mentioned before, the reason why this thread was started in the first place.

 

[Mike PhillipsMike Phillips is verified member.]

As there's little flex in the Rupes pad, it does take a bit of getting used as they don't hug the surface like softer pads,

Yep - that's how sharp foam cutting pad feel when you buff. Same would apply to the RUPES UHS pads and the Lake Country GREY Force Hybrid pads.

After they break-in the feel better when buffing. The "breaking-in" is the pad becoming softer as the foam becomes wet with product and then they stop doing the thing you want them to do and that is finish out nice.

Wet foam cutting pads are no longer "cutting" pads, they become "finishing" pads -that's why you have to switch out often to a "dry" pad. I shared this on my Facebook page this weekend with a 2011 Corvette I detailed.




Thank you for updating and for those following along, here's the link to the other thread.

Gelcoat Polish Question - Removed swirls but also deep gloss? - Pics