- Joined
- Jul 27, 2012
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- 3,094
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- Location
- Brisbane - Australia
- My Car
- 1973 Mustang Convertible
Hey Mark,
This one's for you and Kevin, and any other Forum folk who are interested.
First up, i was going to mention before that sand scratches tend to show up more so, in lighter colors (metallics/ pearls/ solids) than darker ones. Any light silvery colored metallics and pearls are the worst for revealing them.
Now a little on hand sanding. - The human hands are a fantastic ,versatile tool as a sanding aid. Used properly, they deliver a top result for the final finish on any paint job. In my college training days, we were taught the proper techniques and procedures to good hand sanding, and good outcomes. The human hand is fairly soft, spongy and fleshy, and is the perfect tool for smoothing down paints for various outcomes and situations in the paint shop.
Block work plays a vital roll to levelling, flattening, shaping and straightening out flat and curved shaped panels for sure. But after a good block work job has been performed correctly, you will still have surface imperfections in the putty or primed substrate. They could be for example, block tracking marks created from the edge of the block, or sand scratch marks from using rough grade papers for your block work. So basically, the surface now needs to be finally smoothed down in prep for the application of any top coats. The human hand in conjunction with the correct grade of sand paper is just the thing for smoothing down the putty/ primer to remove any surface imperfections. The end result leaves the surface beautifully , and evenly smooth, ready for any top coats to be applied. Choosing to use soft blocks for final pre top coat sanding works quit well for flat surfaces mainly, but can't compete to using your hands. The hands will do all flat or curved concave or convex contours and any edges to perfection. Hand sanding is fantastic also when you want to oil back or level out/ flatten out your top coat, be it clear coat of 2k solid enamel. This procedure is used when you want to remove the orange peel from your final top coat to a peel less flat glossy finish. There are a few more apps where hand sanding holds its own perfectly, which i won't prattle on about now.
The average sheet of dry or wet & dry sand paper is around 12 inches square i think. The idea is to either cut the paper into quarters or halves depending on your application. Most of the time your will be using quarters. Halves are useful when you are hand sanding down panels and you are using the fingers and palms of your hand together. Halves are also good when you want to fold them into quarters. The idea here is that the folded up side of the paper, now provides a useful non slip function, gripping onto your skin more, and preventing the paper from slipping or moving around in your hand when you are sanding. Most of the time painters who hand sand, will use the flat of their closed fingers and maybe a little of the front palm as well. Below, i have given two separate charts explaining firstly the various parts of the human hands that can be used for various sanding applications, and secondly, the correct and incorrect positions of the hands when sanding. These apply for both wet and dry sanding as well. Usually, the paper is held onto the hand by gripping one corner of the quarter sheet or half sheet folded, between the side of the thumb and the first finger. This is a common approach, and works well to secure the paper to your hand when sanding out your panels.
Lastly, modern day spray shops have embraced the use of air driven tools to assist and speed up the production times of refinishing cars. Dry sanding with dust extraction, and wet sanding is the thing now, and machines like DA sanders are very popular for sanding down panels for various procedures. For example, they are commonly used for final or detail sanding before the application of any top coats. They do save considerable time and energy, and deliver a pretty good job. This has caused the old way of hand sanding to fade into obscurity somewhat, and so hand sanding is fast becoming a dying art or a thing of the past. I use air driven tools myself for different sanding apps, but still use hand sanding to prep up my jobs. The interesting thing in my opinion, is that modern day air sanding tools deliver good and fast results for sure, but there is no substitute for the quality and the final appearance of using your hands for hand sanding panels.
See my charts below...........................
Many thanks,
Greg.
This one's for you and Kevin, and any other Forum folk who are interested.
First up, i was going to mention before that sand scratches tend to show up more so, in lighter colors (metallics/ pearls/ solids) than darker ones. Any light silvery colored metallics and pearls are the worst for revealing them.
Now a little on hand sanding. - The human hands are a fantastic ,versatile tool as a sanding aid. Used properly, they deliver a top result for the final finish on any paint job. In my college training days, we were taught the proper techniques and procedures to good hand sanding, and good outcomes. The human hand is fairly soft, spongy and fleshy, and is the perfect tool for smoothing down paints for various outcomes and situations in the paint shop.
Block work plays a vital roll to levelling, flattening, shaping and straightening out flat and curved shaped panels for sure. But after a good block work job has been performed correctly, you will still have surface imperfections in the putty or primed substrate. They could be for example, block tracking marks created from the edge of the block, or sand scratch marks from using rough grade papers for your block work. So basically, the surface now needs to be finally smoothed down in prep for the application of any top coats. The human hand in conjunction with the correct grade of sand paper is just the thing for smoothing down the putty/ primer to remove any surface imperfections. The end result leaves the surface beautifully , and evenly smooth, ready for any top coats to be applied. Choosing to use soft blocks for final pre top coat sanding works quit well for flat surfaces mainly, but can't compete to using your hands. The hands will do all flat or curved concave or convex contours and any edges to perfection. Hand sanding is fantastic also when you want to oil back or level out/ flatten out your top coat, be it clear coat of 2k solid enamel. This procedure is used when you want to remove the orange peel from your final top coat to a peel less flat glossy finish. There are a few more apps where hand sanding holds its own perfectly, which i won't prattle on about now.
The average sheet of dry or wet & dry sand paper is around 12 inches square i think. The idea is to either cut the paper into quarters or halves depending on your application. Most of the time your will be using quarters. Halves are useful when you are hand sanding down panels and you are using the fingers and palms of your hand together. Halves are also good when you want to fold them into quarters. The idea here is that the folded up side of the paper, now provides a useful non slip function, gripping onto your skin more, and preventing the paper from slipping or moving around in your hand when you are sanding. Most of the time painters who hand sand, will use the flat of their closed fingers and maybe a little of the front palm as well. Below, i have given two separate charts explaining firstly the various parts of the human hands that can be used for various sanding applications, and secondly, the correct and incorrect positions of the hands when sanding. These apply for both wet and dry sanding as well. Usually, the paper is held onto the hand by gripping one corner of the quarter sheet or half sheet folded, between the side of the thumb and the first finger. This is a common approach, and works well to secure the paper to your hand when sanding out your panels.
Lastly, modern day spray shops have embraced the use of air driven tools to assist and speed up the production times of refinishing cars. Dry sanding with dust extraction, and wet sanding is the thing now, and machines like DA sanders are very popular for sanding down panels for various procedures. For example, they are commonly used for final or detail sanding before the application of any top coats. They do save considerable time and energy, and deliver a pretty good job. This has caused the old way of hand sanding to fade into obscurity somewhat, and so hand sanding is fast becoming a dying art or a thing of the past. I use air driven tools myself for different sanding apps, but still use hand sanding to prep up my jobs. The interesting thing in my opinion, is that modern day air sanding tools deliver good and fast results for sure, but there is no substitute for the quality and the final appearance of using your hands for hand sanding panels.
See my charts below...........................
Many thanks,
Greg.
