Sandblasting advice needed.

[midwest]

I am wanting to put a spray in bed liner in my 86 K20. The issue is the donor bed I obtained and have on it had a DIY herculiner type liner put on it before I bought it, years ago. 80 % of it has worn off as the bed floor is basically bare meatal but the bedsides and wheel wells that don't get much abuse are still covered pretty much. At first I was just going to have it sandblasted but a friend of mine says not to sandblast because the remnants of the sand will be around forever. He said the only thing I should do is dustless blasting, if I am not going to try to remove it myself. I called a dustless blast place and the said even if you use dustless there is still particles similar to the sand, and the only reason to use dustless over standard sandblasting is the dustless won't warp or hurt the metal. The interior of the bed is not in perfect shape so I can't imagine a professional sand blaster would do enough damage to notice, especially once a liner is sprayed on. I just don't have the time to use some type of chemical and peel it off by hand. The dustless blast places around me are booked up for several months.

So what are your guys thoughts on having the bed sandblasted. I spoke with the Rhino liner dealer near me and he said as far as the surface, sand blasting is preferred because it roughs the surface a little and the liner will stick better. He said they do a lot of farm equipment and other "non vehicle" applications and they always recommend it be sand blasted before being brought in. He said almost all the truck beds they do are newer so they just scuff those and go.

 

[midwest]

Just to update, since I typed the above. I called a local sandblasting place. He asked what year the truck was and told him an 86. He said the metal on these beds is not thick enough to handle sandblasting and said it would damage the metal before getting all the old liner off. Not sure if he just told me that because he didn't want to work or if that's the case. He said, even if you brought it to me I would turn you away because I think I would tear your bed up. Assuming he truly feels that way I appreciate the honesty but feel like the metal on the bed of a truck could hand sandblasting, but then again I know nothing about sandblasting.

 

[shiftpro]

Many of us have been sandblasting fendera and what not for decades. Maybe of the sandblasting company only does bridges and heavy industrial... and they would be using really high pressures and a heavy coarse medium. The application has to be suitable for the material.
I have sandblasted very old rusty headers, carefully and with a small blaster and just barely enough air pressure to get it done. Heat paint on the headers and there's another ten years of service. The biggest limit to home sandblasting is the reserve of air. Old pressure tanks or depending on location, auto propane tanks can be had for a chicken sandwich. Hang the tanks from the rafters and tie them all in together.

 

[shiftpro]

Don't send a raging bull into a china shop.

 

[Blue Ox]

As stated, lots depends on the media and pressures. I don't think that residue is a huge concern. It's not an oil pan. However if it is, look into dry ice blasting.

Another thing. If the bed liner is kind of rubbery, it's hard to strip with most media blasting. Also, what kind of shape is the metal in. What looks like surface corrosion on sheet metal can quickly turn into Swiss cheese.

 

[waterpirate]

My recent rabbit hole is removing the factory/dealer undercoating on a 55 studebaker coupe. Of all the methods tried failed. The best result is using a cheapo vibrating cutter with a straight blade. We are holding it loosely and using the side edge to chip away the crap. I believe that the coating is asbestos and lead mixed together with some sort of Dupont super glue of the era. lol
Eric

 

[midwest]

From what I can see of the metal it appears to be good, however sometimes you don't know until you get to the surface. Here are a couple pics of the beds current state... The liner that is in it now doesn't have a rubbery feel. It is on very thin and feels more like hardened sand paper then some of the rubber textures I have felt.

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[Corvette Ed]

My recent rabbit hole is removing the factory/dealer undercoating on a 55 studebaker coupe. Of all the methods tried failed. The best result is using a cheapo vibrating cutter with a straight blade. We are holding it loosely and using the side edge to chip away the crap. I believe that the coating is asbestos and lead mixed together with some sort of Dupont super glue of the era. lol
Eric

I think using this method while applying some heat ( heatgun,torch etc ) should do the trick.

 

[WP29P4A]

These work really well, come in different grit size as well as larger diameter for different size tools. They could be helpful to get down to metal in a few spots so you have a starting place with the media blaster. Powder coating and rubberized coating are not easy to remove with media blasting unless you use a chemical to destabilize the surface, or something abrasive.

media blasting can bounce off certain finishes like Powder coating and rubberized paints unless it is fairly aggressive in grit and hardness which is really hard on sheet metal. If you loosen the finish first you can work from the loose areas to remove the finish. Trying to blast through the finish as a starting point is slower than finding the edge of the finish and working from there. I used a sand blaster to remove powder coating from a few small motorcycle brackets, barely took off the shine and didn't come close to removing the finish, had to soak them in acitone to loosen the finish so I could blast them clean.

Removing paint is easy, other finishes make you work for it, especially if the product was applied correctly.

 

[Gman73]

It's a ton of work but I've done a few beds with a wire stripper and a angle grinder, comes out super nice just wear plenty of protection or you'll look like a porcupine.

 

[BearKing]

There are different kinds of media being used in sand blasting equipment. I have seen walnut shells used and it works great. I used own my own body shop many years ago and never had any trouble with warping old steel from classic trucks/cars. As someone pointed out before, pressure and type of media PLUS experience are all factors in getting the job done.

 

[CalSgt]

Chemical stripper maybe? Just an idea, not sure if it will strip bedliner though

 

[midwest]

Thanks for the replies, got side tracked and still haven't done anything with the bed. Rhino liner had a sale that ended the middle of February and once I missed that deadline I quit looking. I had a wiring issue I just got fixed tonight (I lost all my lights to the rear end, found a bad ground wire). Now that the lights are working again I can take the truck to some places to see if they can get it out.

 

[mtbadbob]

Try Garnet or Walnut shells. I found Garnet to be the most aggressive without any substrate damage. A power washer will wash the residue away, I wouldn't be concerned, it's not a '63 Split-window you're trying to refinish!

 

[ali_c20]

I use heat and different sized scraping blades/gasket removers for bedliner, rubberized undercoat and all flexible paints. Takes some time but it's not that much of mess. For smaller parts a good airgun does the trick for bigger parts the big propane torch.