Best Undercoating?

Doublebase · April 19, 2018

21 hours ago, 1940ModelB said:

Word has it Fluid Film dissolves the wax coating GM uses on our frames and takes a bad situation and makes it worse.

Thanks, didn't know that.

WesternMike · April 20, 2018

My frame is full of surface rust on my 2014 now.

I’m about to do a massive lift and want to strip and coat the frame finally.

How did you guys remove the surface rust? Just get under it with a wire wheel?

Brown4x4 · April 20, 2018

I noticed that these trucks also have a sound deadening material that absorbs salt and moisture at the bottom of the front fender. It's the area between where the front mud flap and front door seam would be. You can see it if you open your door and look in the seam where your hinge is near the bottom. I removed the mud flap and front wheel liner to access this spot and removed the sound deadening material. The material was soaking wet and could have made that area rust out. I now keep the area soaked with Krown spray.

adamj2121 · April 20, 2018

3 hours ago, WesternMike said:

My frame is full of surface rust on my 2014 now.

I’m about to do a massive lift and want to strip and coat the frame finally.

How did you guys remove the surface rust? Just get under it with a wire wheel?

I did my truck before there was any surface rust. Let me say to begin with, stripping the factory wax off is one of the most annoying things I have ever done. I found the best way to get the wax off was to spray with a solvent, let it sit, and then use a pressure washer (preferably heated) to knock the wax off and repeat the process until all of the wax is gone. I used a mixture of diesel fuel and Purple Power cleaner as my solvent and it worked pretty well, the diesel really softens up the wax.

As far as the areas that already have rust I would do one of 2 things depending on how bad it is. If it is very minor surface rust I would just spray it with a rust reformer. If it is really bad and rough I would sand it down with a wire wheel, sanding block, etc and then spray with a rust reformer (if rust is still visible).

Edited April 20, 2018 by adamj2121

pickmeup · April 20, 2018

Brake Cleaner sold in aerosol cans will soften and loosen it right up.

dave07 · April 20, 2018

Thanks, didn't know that.

I have been using fluid film on my frame for about 2 years now. It didn’t dissolve the wax on my frame at all. However it doesn’t really hold up from the constant barrage of salt/anti skid which seems to blast it off easily.

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WesternMike · April 20, 2018

I did my truck before there was any surface rust. Let me say to begin with, stripping the factory wax off is one of the most annoying things I have ever done. I found the best way to get the wax off was to spray with a solvent, let it sit, and then use a pressure washer (preferably heated) to knock the wax off and repeat the process until all of the wax is gone. I used a mixture of diesel fuel and Purple Power cleaner as my solvent and it worked pretty well, the diesel really softens up the wax.

As far as the areas that already have rust I would do one of 2 things depending on how bad it is. If it is very minor surface rust I would just spray it with a rust reformer. If it is really bad and rough I would sand it down with a wire wheel, sanding block, etc and then spray with a rust reformer (if rust is still visible).

The wax flaked entirely off within months. Was one of the problems with the first Gen of these trucks (2014). My truck was perfect besides this rust issue on the frame.

I don’t think it’s too bad so now that it’s getting warm up here in Alberta I may try to tackle this as soon as I get the 8” lift on; will be so much easier being under it after lifted haha

dave07 · April 20, 2018

The wax flaked entirely off within months. Was one of the problems with the first Gen of these trucks (2014). My truck was perfect besides this rust issue on the frame.

I don’t think it’s too bad so now that it’s getting warm up here in Alberta I may try to tackle this as soon as I get the 8” lift on; will be so much easier being under it after lifted haha

I wonder if the 2019s have the same wax on the frames?

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adamj2121 · April 20, 2018

1 minute ago, WesternMike said:

The wax flaked entirely off within months. Was one of the problems with the first Gen of these trucks (2014). My truck was perfect besides this rust issue on the frame.

I don’t think it’s too bad so now that it’s getting warm up here in Alberta I may try to tackle this as soon as I get the 8” lift on; will be so much easier being under it after lifted haha

The 8" lift will make it much easier. I have a 6" lift and I drove the truck up on some wood blocks I had laying around, so it was about 12" in the air and it was super easy.

adamj2121 · April 20, 2018

2 minutes ago, dave07 said:

I wonder if the 2019s have the same wax on the frames?

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It's hard to say, GM has been using the wax for so long I really doubt they will change. I think it would be beneficial for the consumer if they would switch. The e-coating that Ford uses seems to be pretty nice.

pickmeup · April 20, 2018

24 minutes ago, dave07 said:

I wonder if the 2019s have the same wax on the frames?

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Quite sure they stated they are going to continue the wax coating as they believe in it .

xax · April 20, 2018

krown undercoating is king is canada at least

Doublebase · April 20, 2018

4 hours ago, dave07 said:

I wonder if the 2019s have the same wax on the frames?

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I don't know what's on the 2019's but the sales guy that sold me my 2018 last weekend said that the frames have a new undercoating on them for 2018. Don't know if that's true, doubt it seeing as how the guy didn't know what direct injection was or that the truck had electric steering. Pointed that out to him and he said no, it's got regular sterring. Asked him to point to the power steering pump and he pointed to the water pump.

But the frame does have a very tacky black coating on it...doesn't seem to be working as there already is rust in spots were the coating has rubbed off.

Doublebase · April 20, 2018

4 hours ago, dave07 said:

I have been using fluid film on my frame for about 2 years now. It didn’t dissolve the wax on my frame at all. However it doesn’t really hold up from the constant barrage of salt/anti skid which seems to blast it off easily.

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Yeah I haven't sprayed it over undercoating or anything - then again maybe I have - I just have used it on the pinch welds on my car right before winter starts. Seems to do ok, nothing special. I kind of look at it as a temporary solution that needs to be reapplied. I think most stuff will work temporarily...oil, penetration oil, rtv, grease, paint...but none of those is a long term set it and forget, fix.

I had a leaking oil pan on an Accord I used to own, that oil pan was probably the only thing that wasn't rusted on that car.

There's always POR 15. But get any of that on you and it's never coming off, lol.

Donstar · April 21, 2018

My '15 does not appear to have any type of coating that could peel off and no signs of unusual amounts of rust. Other than the obvious appearance issues, has anyone experienced any functional issues related to rust on a newer vehicle? Many years ago I had a '76 GMC 3/4 ton and my mechanic once showed me my floor mats from underneath the truck while up on a hoist. I put a few pieces of plywood under the mats and kept on trucking!