# sanding



## jhold87 (Jul 1, 2012)

Im about to start a new build and the body is pretty bad and will need sanding and putty.My question is what grit paper and in what order do i use it in?Thanks for any help.


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## harristotle (Aug 7, 2008)

I'd be curious to hear the answer to this. 

The paint on a hot rod I'm building is done except needing wet sanded. Just don't know what grit to use...


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## jhold87 (Jul 1, 2012)

Anyone?


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## Zombie_61 (Apr 21, 2004)

Rule of thumb regarding sandpaper: The higher the "grit number", the finer the grit is. For example, 400 grit will give you a smoother finish than 200 grit.

As for which grit to use, that's a matter of personal preference. I generally start with 150 or 180 grit for shaping because coarser grits can leave deep scratches that require more work to obliterate. Then I move to 220 grit to refine the surface once I've achieved the proper shape, then move to 400 grit. Final sanding with 400 grit gives me a surface that's smooth enough for my tastes, but some modelers prefer 600 or 800 grit.

Hope this helps!


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## CorvairJim (Dec 16, 2011)

harristotle said:


> I'd be curious to hear the answer to this.
> 
> The paint on a hot rod I'm building is done except needing wet sanded. Just don't know what grit to use...


For wet sanding the paint, go NO COARSER than 600 grit! I usually start with 1200 and work my way up from there through several progressively finer grades. I hve a 'polishing kit' with 6 grades of polishing cloths, which are actually cloth-based 'sandpaper'. I follow that up with fine polishing compound diluted with plain water, then Meguair's automotive polish. A coat of car wax is a good idea fo protection from damage from exposure to light, but never wax ANY paint until it's been allowed to dry for at least 2 months, to allow it to completely gas out.


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## SteveR (Aug 7, 2005)

Got pictures?


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## djnick66 (May 2, 2008)

If you are trying to take down mold seams, putty, etc. you are wasting your time with fine grit paper. Get some wet and dry in 320 to 360 grit for the main work. This will cut down the putty and plastic fairly easily and quickly. Then polish up the areas with finer grits and you can follow up with some tooth paste and an old cotton tee shirt too. 

For polishing painted surfaces, they make some ultra fine micro clothes that go up to something like 2000 grit.


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## scottnkat (May 11, 2006)

for polishing after you've done the initial sanding, they make some even finer. For instance, the Micro-Mesh polishing kit has grits that include 3200, 3600, 4000, 6000, 8000, and 12000 grit - these extra fine grits are helpful for polishing out blemishes in clear parts as well and making them clear again


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## robiwon (Oct 20, 2006)

For polishing paint I also have the Micro Mesh system, the cloths and the foam pads. Best thing in the world for paint, next to a polishing compound.


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## MadCap Romanian (Oct 29, 2005)

Hi!

Over the years, I have develpoed a good way for getting rid of seam lines over two glued together parts. 

First off, I usually do a "Dry Fit" of the parts to make sure they line up propperly when put together.

Look over the kit and then ask yourself "Do all the alignment pins match up and the two parts meet end to end and top to bottom?"

If not, then cut off and file down the alignment pins, removing them from the whole "alignment" process, and then "eyeball" the part alignment and glue together using Testor's Liquid Glue. (I'm thinking 18"er Enterprise Warp Engine Nacelles here guys!)

For tools, I have made a very rigid sanding block useing a piece of sticky back 180 grit automotive sand paper wrapped around a block of MDF hard board. I like to call this block "The Anihilator" for good reasons! 

But seriously, you should start with sandpaper grit of 240-320. 

Once your glue has dried (24 hours), you can then sand using the "Cross Sanding" method that I was taught in Autobody Collision Repair back in the 1990's. 

Basically, you sand out the seam line by moving the sanding block at a 45 degree angle across the seam line, something like this : ////////////.

Secondly, turn the sanding block around and sand across the seam line in the opposite direction, like this : \\\\\\\\\\\\\.

Your final sanding pattern should look like this : XXXXXXXXXXXXXX

Feel out the seam line using your finger moving it in a vertical direction across the seam line, like this : llllllllllllllllllll

You should not be able to feel the transition (Bump) between the two parts. If you do, repeat the cross sanding process until you can't. 

To remove the deeper scratches created by the 180-320 grit sand paper, use progressive sand papers starting with 400 grit up to 800 grit. 

For seam lines on smaller parts, I usually remove these by scraping them off with my hobby knife and then sanding them with finer sandpaper, if possible.

This being said, I find that by using the cross sanding method, I use less filler to pretty much none at all. I find that I only need filler if there is a sink mark on the model that is so low that I would end up making the plastic paper thin to get to it, or if there's a huge gap between the seam lines.


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