Prepping trailer fenders for paint

[Duane D]

I would strongly recommend you do NOT order that paint kit sight unseen. I work for a major coatings company in the automotive refinish division. White is an extremely difficult color to match for vehicles in general and impossible to do with a pre-mixed kit off the internet. You would probably end up with shiny fenders in the end, but I can all but guarantee that it will be different enough from the rest of your trailer that you will notice it (it is amazing how a subtle difference in white can make such a huge impact when two panels are compared). The kit you are looking at is meant to be sprayed out of an automotive refinish spray gun. How are you planning on applying the paint? The kit also has a hardener with it which means that you have a limited amount of time to be able to spray the paint correctly before it begins to set up and solidify.

I would recommend visiting an automotive refinish store (also called Jobber store) and talking to someone inside. They will be very knowledgeable about how to prep correctly for adhesion and gloss and they will be able to give you an accurate match if you can bring one of the fenders to them. Fiberglass is not much different to paint on top of than bumpers on cars or other parts. Lots of people out there are building fiberglass hot rods and have been repairing Corvettes since 1953 so fiberglass trailer fenders are not out of the ordinary for an automotive paint technician or jobber store clerk to handle. I would also bet that someone inside a jobber store near you does paint work on the side in their house and they could do a great job for you if you don't have the correct equipment or skills.

I would be glad to offer step by step advice privately if you would like to tackle this yourself - just shoot me a PM.

[supturb89]

What's a good way to remove the adhesive left behind from the slip guards on the fenders? I removed one last fall and the the adhesive didn't pull off with it. Was thinking kerosene may be good? I have a feeling they are all going to be like this.

[supturb89]

Originally Posted by Duane D

I would strongly recommend you do NOT order that paint kit sight unseen. I work for a major coatings company in the automotive refinish division. White is an extremely difficult color to match for vehicles in general and impossible to do with a pre-mixed kit off the internet. You would probably end up with shiny fenders in the end, but I can all but guarantee that it will be different enough from the rest of your trailer that you will notice it (it is amazing how a subtle difference in white can make such a huge impact when two panels are compared). The kit you are looking at is meant to be sprayed out of an automotive refinish spray gun. How are you planning on applying the paint? The kit also has a hardener with it which means that you have a limited amount of time to be able to spray the paint correctly before it begins to set up and solidify.

I would recommend visiting an automotive refinish store (also called Jobber store) and talking to someone inside. They will be very knowledgeable about how to prep correctly for adhesion and gloss and they will be able to give you an accurate match if you can bring one of the fenders to them. Fiberglass is not much different to paint on top of than bumpers on cars or other parts. Lots of people out there are building fiberglass hot rods and have been repairing Corvettes since 1953 so fiberglass trailer fenders are not out of the ordinary for an automotive paint technician or jobber store clerk to handle. I would also bet that someone inside a jobber store near you does paint work on the side in their house and they could do a great job for you if you don't have the correct equipment or skills.

I would be glad to offer step by step advice privately if you would like to tackle this yourself - just shoot me a PM.

Thanks for the advice. I'm planning on painting the entire trailer. Planned to use this HVLP gun from HF. I'm having the trailer blasted and then plan on priming with this, followed by the paint above. Not looking for showroom quality, just better than what it is currently, which shouldn't be too hard to do.

[Duane D]

3M and other companies make adhesive removal products that are not too expensive that are designed to remove adhesive from moldings and emblems on the sides of cars. Kerosene or gasoline will work too, they just leave a greasy film behind that should be cleaned off as well. Not to mention dangerous to use. Anything that is solvent-based like mineral spirits, terpentine, paint reducer, etc. will all soften up the adhesive from the rubber pad enough to scrape it off with your fingernail. Be careful not to let any of these items get on stickers, vinyl or decals that are on your boat or trailer as they will distort and potentially discolor them.

[Duane D]

Originally Posted by supturb89

Thanks for the advice. I'm planning on painting the entire trailer. Planned to use this HVLP gun from HF. I'm having the trailer blasted and then plan on priming with this, followed by the paint above. Not looking for showroom quality, just better than what it is currently, which shouldn't be too hard to do.

If you have a small amount of ability with doing these kind of things, it shouldn't be too much trouble. The primer you showed is an epoxy which has excellent corrosion protection properties. These primers are designed to be applied to bare steel and the overcoated with a surfacer or top coat. Epoxy primer does not have to be sanded to be overcoated.

The gun you have linked up there will work for what you are doing, but keep in mind that spray guns that automotive paint technicians use cost $500-$800.00. Your compressor should be at least 2 HP to provide enough air for the consumption that gun requires (6 CFM - cubic feet per minute).

If you go slow, take your time and remember "less is more" you should do just fine. Don't try and put all the paint on at one time, you can always add another coat. Once it comes out of the gun, though you can't put it back in. There will be an adjustment on the gun to restrict the motion of the trigger. I highly recommend you turn that knob in at first until you get used to how fast the paint gets on the panel so you don't creat unnecessary work for yourself to fix runs. Remember to bend down and spray the bottom and the insides of the trailer as well. If you don't it will rust through on you in an astonishingly short amount of time.

Looks like a fun project that you can do yourself and will make a big difference for the looks of your rig. Let me know how it turns out and I will help any way I can as you get started.

[supturb89]

Originally Posted by Duane D

If you have a small amount of ability with doing these kind of things, it shouldn't be too much trouble. The primer you showed is an epoxy which has excellent corrosion protection properties. These primers are designed to be applied to bare steel and the overcoated with a surfacer or top coat. Epoxy primer does not have to be sanded to be overcoated.

The gun you have linked up there will work for what you are doing, but keep in mind that spray guns that automotive paint technicians use cost $500-$800.00. Your compressor should be at least 2 HP to provide enough air for the consumption that gun requires (6 CFM - cubic feet per minute).

If you go slow, take your time and remember "less is more" you should do just fine. Don't try and put all the paint on at one time, you can always add another coat. Once it comes out of the gun, though you can't put it back in. There will be an adjustment on the gun to restrict the motion of the trigger. I highly recommend you turn that knob in at first until you get used to how fast the paint gets on the panel so you don't creat unnecessary work for yourself to fix runs. Remember to bend down and spray the bottom and the insides of the trailer as well. If you don't it will rust through on you in an astonishingly short amount of time.

Looks like a fun project that you can do yourself and will make a big difference for the looks of your rig. Let me know how it turns out and I will help any way I can as you get started.

Thanks for taking the time to write this up. I may have some questions once I get everything here and ready to go. I'm glad to hear that about not needing to sand the primer. I'm trying to do this as cheap as possible without resorting to the rattle cans. I think this way will still come out ahead in terms of looks and maybe even price over the rattle can method.

Once I get the boat back home I will try to restore the fenders before giving up and painting them. If I do have to paint them would the epoxy primer be good on the fiberglass as well?

Thanks again!

[supturb89]

One more thing. The link to the paint I referenced above was for a single stage urethane. They also have an acrylic enamel, which one would be the better to use?

[Duane D]

Epoxy is fine over fiberglass, you will not have an issue there. Fiberglass is very porous if you sand all the way down through the existing paint, so it may look better if you add an extra coat to the fenders in these areas.

Single stage urethane looks better and is much more durable than acrylic enamel. Think 1990s technology (urethane) vs 70s technology (enamel) or CDs vs 8-tracks. Enamel is very brittle and wont stand up well over time to any flexing the trailer may do as you load and unload the boat.

One important thing I left out above is to clean, clean and clean again before painting. Paint can only stick to what is underneath it so you want to get all the dust cleaned out and any contaminants off the surface before you begin painting with the epoxy primer. You will need a good water-based cleaner (soap and water or dish detergent work fine for this project) and you also need a solvent-based wax and grease remover. If you touch bare steel with your hands/fingers, you will leave oils from your skin behind that only wax and grease remover can get out. Water based cleaner gets the other contaminants off that wax and grease remover won't get.

[supturb89]

Originally Posted by Duane D

Epoxy is fine over fiberglass, you will not have an issue there. Fiberglass is very porous if you sand all the way down through the existing paint, so it may look better if you add an extra coat to the fenders in these areas.

Single stage urethane looks better and is much more durable than acrylic enamel. Think 1990s technology (urethane) vs 70s technology (enamel) or CDs vs 8-tracks. Enamel is very brittle and wont stand up well over time to any flexing the trailer may do as you load and unload the boat.

One important thing I left out above is to clean, clean and clean again before painting. Paint can only stick to what is underneath it so you want to get all the dust cleaned out and any contaminants off the surface before you begin painting with the epoxy primer. You will need a good water-based cleaner (soap and water or dish detergent work fine for this project) and you also need a solvent-based wax and grease remover. If you touch bare steel with your hands/fingers, you will leave oils from your skin behind that only wax and grease remover can get out. Water based cleaner gets the other contaminants off that wax and grease remover won't get.

Will go with the urethane. Will lacquer thinner be good for the wax and grease remover?

[Duane D]

Some carb & choke cleaner or brake cleaner would work better than straight lacquer thinner. They have "scrubbers" in them that get in and attack contaminants and lift them to the surface so you can cleanly wipe them away.