Long blocks upgrade??

RosharonRooster

Promoted Users
Good evening. I work on cars that are 18ft long and ive been using durablocks for blocking. Im happy with the results but im kind of OCD and always chasing the best results. Any recommendations on long blocks (12 inch or longer)? Ive read where people mention hard blocks. Are durablocks not hard blocks? Just looking for advice. Thanks
 
Some blocking tips we did when blocking out doors:



We had already done a couple sessions of priming/blocking the door across to the quarter and to the fender, all installed on the car. After this, more primer and put a perimeter of tape on the door skin. Now block separately, and the tape allows you to block the door and keep off the edge to prevent losing your match to the fender/quarter.


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I don't stick with 45* angles, if you want to keep a long direction flat, you need the long block to better follow that direction. So change up to some sharper angles, about 30* off the long direction every now and then. Work one end to the other, consistent spacing, consistent angle, end to end. Then alternate to passes in the opposite direction.


Once done, and the inner part is good and blocked, now remove the tape and GENTLY block to the edge, taking care to not pull down at the edge and round things back off again. Whatever hand is holding the block make sure it is minimal pressure and stays on the door skin. In other words, no pressure pulling down past the edge.


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One other point, to keep the inner end of the sanding block from sanding out all your hard work in the center of the door, put a wrap of tape around the end of the sanding block that is towards the center of the door. This helps that end to glide across the center of the door without cutting primer there.


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Now to show the importance of the long board..


We had done some blocking with the 27" AFS and seemed to have two high spots with a low in the middle of the door..

Note the high areas marked by the green tape...


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Now we can see that as the sander is moved to the left, the left portion of the AFS is over the high spot on the left, and a bit more movement and the right portion of the AFS will start dropping into the low void. Effectively, this is still cutting material out of the low, keeping it low.


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Looking at the next size up, a 36" AFS....


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Here we can see this one does a much better job of spanning the high spots and staying up on top of the high spots, for a more effective job of knocking down the highs and leaving the low in the center alone...


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After a few horizontal passes at slight angles, like so with the 36".......


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We follow up with some vertical passes at slight angles with the 27".... all rods removed to better follow the contour. Then alternate back to the 36 and another horizontal session..

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SO the point of all this babbling is that for long panels especially, use as long a block as you can stand. I have also found the Mirka Gold tends to load up rather quickly, I've had best luck with the 3M blue... When you have a 36" or longer block, you don't want to waste a bunch of time (and PSA paper) because it loads up too quickly...
 
In case anyone is wondering, the AFS blocks are NLA. From what I've heard, the owner/inventor of them died and no other company one has picked them up and continued producing them. They are extremely hard to find. I've been looking for a set for a few years now with no luck.
You could also try making your own. Acrylic sheet works well.
 
I've been making my own blocks out of plexiglass and wouldn't go back to anything else. The thinner ones flex enough to match any rounded shape (VW Bug fenders or even rounder surfaces are no problem), the thicker ones are stiff enough to straighten flat panels, and the surface is hard so it forces the paper to cut the high spots very effectively. They also flex in a natural arc so they shape/sand curved shapes evenly. Foam blocks and even the AFS foam blocks with a thin spring steel face can be soft enough that the foam acts like "suspension" and absorbs high spots instead of cutting them flat. Plexiglass blocks are absolutely unforgiving in that regard- they won't absorb high spots and if the correct technique and thickness block is used for the panel it won't dip into low spots. They're also fantastic for cutting all orange peel out of clear for the same reason; they don't absorb the texture and "round over" the orange peel like foam blocks, the hard surface forces the paper to cut every bit of texture out.

Just a few I've made, I probably have 25-30 of them in various lengths, widths, shapes, and thicknesses ranging from .050" to 3/8". The handle is Gorilla Tape in a T shape and I've glued 1/4" dense foam on the back of the longer blocks so they're more comfortable when blocking large areas.

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This one is for a truck bed floor- three pieces held together with duct tape so the sides can pivot and match the angle of the ribs in the bed floor.

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Even at really low angles there are no ripples using plexiglass blocks. This is slicksand blocked from 80 to 400 then wiped with wax and grease remover to check the reflection.

 
I've been making my own blocks out of plexiglass and wouldn't go back to anything else. The thinner ones flex enough to match any rounded shape (VW Bug fenders or even rounder surfaces are no problem), the thicker ones are stiff enough to straighten flat panels, and the surface is hard so it forces the paper to cut the high spots very effectively. They also flex in a natural arc so they shape/sand curved shapes evenly. Foam blocks and even the AFS foam blocks with a thin spring steel face can be soft enough that the foam acts like "suspension" and absorbs high spots instead of cutting them flat. Plexiglass blocks are absolutely unforgiving in that regard- they won't absorb high spots and if the correct technique and thickness block is used for the panel it won't dip into low spots. They're also fantastic for cutting all orange peel out of clear for the same reason; they don't absorb the texture and "round over" the orange peel like foam blocks, the hard surface forces the paper to cut every bit of texture out.

Just a few I've made, I probably have 25-30 of them in various lengths, widths, shapes, and thicknesses ranging from .050" to 3/8". The handle is Gorilla Tape in a T shape and I've glued 1/4" dense foam on the back of the longer blocks so they're more comfortable when blocking large areas.

EwFNedKh.jpg


aG6Gq0mh.jpg


VUAU2Reh.jpg


yzTyx2eh.jpg



This one is for a truck bed floor- three pieces held together with duct tape so the sides can pivot and match the angle of the ribs in the bed floor.

Wkjmnzth.jpg


38vAxCHh.jpg



Even at really low angles there are no ripples using plexiglass blocks. This is slicksand blocked from 80 to 400 then wiped with wax and grease remover to check the reflection.

quick question, trying to learn hear. what solvent did you spray on the panel in the video to gloss it. Iam assuming that is poly you sprayed it on. just trying to understand. some folks say dont spay anything on poly for fear of the solvent soaking into it. and giving issues down the road.. and then there are others that say the opposite.
 
quick question, trying to learn hear. what solvent did you spray on the panel in the video to gloss it. Iam assuming that is poly you sprayed it on. just trying to understand. some folks say dont spay anything on poly for fear of the solvent soaking into it. and giving issues down the road.. and then there are others that say the opposite.
It's 710 wax and grease remover, and yes it's poly primer. This was just to check reflections, not anytime before shooting anything on top of it so it has plenty of time to evaporate out. There's a solid coat of epoxy under the poly primer to seal any filler underneath as well.
 
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