should i wet sand prior to buffing faded gelcoat

[Benny1963]

im going to clen and use acutting compound then polish and wax
should i wet sand lightly and if so what grit .also what cutting compound should i use .also polishing compound and wax.
its never been cut so the gel coat is thick. and the ox , is bad
thanks bennyb

 

[1730V]

Re: should i wet sand prior to buffing faded gelcoat

What are you trying to do?

 

[burroak]

Re: should i wet sand prior to buffing faded gelcoat

Gel Gloss is an inexpensive product sold at RV stores, Menards, etc. and brings fiberglass to life.

If the finish is particularly nasty, paint shops can provide compounds with the appropriate cutting media. The general, idea when using these, is to remove the dull finish which will leave scratches. The process then is to remove these scratches with finer and finer compounds. It may be harder to find local people in the marine trade to get advice but Corvette owners are ubiquitous. Body shops doing glass work will be a great source of products and advice and will be able to evaluate your needs if you pull the boat to them.

 

[wire2]

Re: should i wet sand prior to buffing faded gelcoat

Yes, start with something aggressive, like 150, dribble or spray water often to clear the paper. Then progress finer, to 400, 600, 1000, 1500 or 2000. Each step removes scratches from the previous.

At this point you'll have a soft shine already, can go directly to polish compound, like 3M Finesse-it or McGuire's.

OR, if you have a power buffer, can stop sanding at 1000, then go to automotive rubbing compound, then polish compound.

Go easy on edges or you'll go through gelcoat.

Complete job with a good quality wax.

 

[burroak]

Re: should i wet sand prior to buffing faded gelcoat

Yes, start with something aggressive, like 150, dribble or spray water often to clear the paper. Then progress finer, to 400, 600, 1000, 1500 or 2000. Each step removes scratches from the previous.

At this point you'll have a soft shine already, can go directly to polish compound, like 3M Finesse-it or McGuire's.

OR, if you have a power buffer, can stop sanding at 1000, then go to automotive rubbing compound, then polish compound.

Go easy on edges or you'll go through gelcoat.

Complete job with a good quality wax.

150 grit....OUCH!

Get professional advice before considering this plan of action.

 

[pgdignan]

Re: should i wet sand prior to buffing faded gelcoat

mothers makes a great liquid buffing compound but it requires a high speed buffer and bonnet, I don't think I'd use 150 grit on the gel coat, that seems like a recipe for disaster.

 

[ondarvr]

Re: should i wet sand prior to buffing faded gelcoat

150 is way too course.

Start with just buffing the surface with a fast cutting compound, see if that works before even picking up any sand paper. If you do need to sand, start with 600 in a small area, after sanding this area buff with compound and see if the color and gloss come back, you may need to sand more, but just do it in small area until you get the results you want. Sometimes you don't need to go any finer than 600 to buff all the scratches out, it depends on the gel coat used on this boat. If the scratches don't buff out, then use finer paper and each time check to see if the sctratches can be buffed out before going to the next finer one.

Many automotive stores carry buffing compounds (NAPA), they're easy to find.

 

[burroak]

Re: should i wet sand prior to buffing faded gelcoat

In a previous post, a cautionary note was sounded about sanding, buffing, or polishing too heavily on the edges and character lines. It's a good point. To prevent burn through, if you are a novice, tape the opposite side of the character line and back off when you notice the edge of the tape beginning to lift. I know it's a PITA but gel coat won't grow back.

 

[wire2]

Re: should i wet sand prior to buffing faded gelcoat

Ok, I'll concede 150 may be too coarse.:redface:

But I wouldn't hesitate to start off with 220. I've found that if you start off too gently, the end result is a "not quite like new" gloss.
And it dulls again within a few months.

Each application is different, a late model boat that has very recently gone dull can be brought back with minimal abrasion.
Conversely, an older boat with deep UV damage will need a more aggressive technique.

Color plays a role too, red is probably the fastest fading pigment out there.

I suppose the solution is to test a small area with "gentle" methods first, see if it comes up and lasts. If not, go at it a bit harder.

 

[BillP]

Re: should i wet sand prior to buffing faded gelcoat

I do it with a high speed 8" disc sander and foam pad. 400 wet and then 600 wet. Follow the 600 by buffing (use a foam pad here too) with course, medium and fine compounds. Final buff is with with a polish.

 

[ondarvr]

Re: should i wet sand prior to buffing faded gelcoat

Actually for myself, I do it more like BillP using power tools, sometimes wet, sometimes dry with a DA or plam sander, as I hate hand sanding.

 

[wire2]

Re: should i wet sand prior to buffing faded gelcoat

I do it with a high speed 8" disc sander and foam pad. 400 wet and then 600 wet. Follow the 600 by buffing (use a foam pad here too) with course, medium and fine compounds. Final buff is with with a polish.

Is that an actual hi speed disk sander, 12,500 rpm?
Or a polisher, 3,000 rpm?

 

[marla0416]

Re: should i wet sand prior to buffing faded gelcoat

It depends on how oxidized it is. We used 400 grit. Boat was beautiful. She was an '88. Never buffed. WOW ! She looked sweet. Be gentle.

 

[Nova II 260]

Re: should i wet sand prior to buffing faded gelcoat

I used 2000 grit, wet sand by hand, then polish with buffer.
Still nice, 21 year old. Relection

 

[Benny1963]

Re: should i wet sand prior to buffing faded gelcoat

thanks for all the info the bottom is white and the top is teal green
gelcoats exc condition
im going to start with 3m cutting for heavy ox and then step to finess
then apply a good wax on a small spot first to see if i need to get more friskee with it and sand first .
thanks everyone benny b

 

[BillP]

Re: should i wet sand prior to buffing faded gelcoat

Is that an actual hi speed disk sander, 12,500 rpm?
Or a polisher, 3,000 rpm?

I think 12K is more about grinders than sanders. My tools are both tagged "polisher/sander" and what you see in commercial shops doing glasswork. I use two, both are 11 amps, one is 2 speed (1500 & 4500 rpms) with 8" disc and the other is a lightweight variable speed (1000-3000 rpms) with a 7" disc. Nothing like the 12K rpm grinders or typical 3000 rpm polishers. I have one of the 3000 rpm polishers and never use it...the others are way more powerful and faster.

"Sorry for the delay...I've been away from this site.

 

[bigboneli]

Re: should i wet sand prior to buffing faded gelcoat

150 grit....OUCH!

Get professional advice before considering this plan of action.

ditto...150 is a little too heavy ...just a little...