Tips on cutting holes in ABS dash

[82_454_shorty]

First off, let me say this is a great site. I've been a long time lurker but I'm finally going to get back at my '82 after a long hiatus. I figure that if I start posting regularly the members will hopefully shame me into staying with it.

I've posted some build pics over on the 'under construction' forum is you're interested in taking a look on my progress to date.

http://www.gmsquarebody.com/forum/showthread.php?t=2704

Now to my post:

I picked up a blank dash plate from Classic Dash:

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Its a nice piece, molded ABS with a finish that's almost like an enamel.

Has anybody had any experience with cutting / drilling this kind of material and if so would you have any suggestions that might help this go smoothly?

I plan on using painter's tape and fine blades or hole saws, and drilling from the finish side back through the backing, but any advice would be welcome.

 

[89Suburban]

Damn imagine the dash mods you could do with that.

Welcome aboard.

 

[skysurfer]

I plan on using painter's tape and fine blades or hole saws, and drilling from the finish side back through the backing.

That's how I would do it. ABS is much more forgiving than fiberglass so you shouldn't have issues with the finished surface chipping on the edges, but a trial cut in the center of a larger area that will later be removed is a good idea.

If your jig saw has an orbit adjustment for the type of material being cut, set it for metal or no orbit. On a high orbit setting for softer materials like wood the blade rocks back and forth for a faster cut but doesn't leave a clean edge.

If the fine-tooth blades leave a rough edge or chips, you can try a carbide grit blade. They act like sandpaper through the material leaving a smooth edge, but you have to carefully control them. They don't have the directional stability of a toothed blade.

 

[82_454_shorty]

Thanks 'surfer'. Love that avatar by the way

 

[8T6K5]

Damn imagine the dash mods you could do with that.

Yes, welcome. You've got a black slate there......

Endless opportunities...guy on my K5 forum just make the sickest dash I've ever seen:

 

[MrMarty51]

 

[chengny]

This is what I've been using:

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It came with a big Ryobi portable workbench/multi tool set I bought years ago. It's primarily intended to make internal cuts in drywall (kind of like a mini plunge router). I hate doing sheetrock so it never got any use.

But then one night I was modifying a dash to accept a DIN style head unit. I had been struggling with hacksaw blades, Dremel tools, utility knives, files, etc.

For whatever reason I thought of the speed saw. It worked pretty good - certainly better than anything else I've used.

It's cordless and light, so you can maneuver it easily. Needs only one hand to operate and using the 1/8" bit lets you get in tight to the corner cuts. To start a cut it just tilts in - or you can drill corner holes.

The bit doesn't really like plastic so you have to go slow to avoid melting it. Also, keep a small wire brush close by, the bit needs to be cleaned after about every 2 inches of cut.

Remove any wavy lines with a coarse file and dial in the final cut with a fine file.

 

[MrMarty51]

This is what I've been using:

You must be registered for see images attach

It came with a big Ryobi portable workbench/multi tool set I bought years ago. It's primarily intended to make internal cuts in drywall (kind of like a mini plunge router). I hate doing sheetrock so it never got any use.

But then one night I was modifying a dash to accept a DIN style head unit. I had been struggling with hacksaw blades, Dremel tools, utility knives, files, etc.

For whatever reason I thought of the speed saw. It worked pretty good - certainly better than anything else I've used.

It's cordless and light, so you can maneuver it easily. Needs only one hand to operate and using the 1/8" bit lets you get in tight to the corner cuts. To start a cut it just tilts in - or you can drill corner holes.

The bit doesn't really like plastic so you have to go slow to avoid melting it. Also, keep a small wire brush close by, the bit needs to be cleaned after about every 2 inches of cut.

Remove any wavy lines with a coarse file and dial in the final cut with a fine file.

Using one of those for cutting around switch/outlet boxes doing drywall,they would hang tight to the box going one direction but going the other way they would drift away from the box,I do`nt remember if it was CW or CCW that it would hang tight to the box.
Be carefull when using one of these just so it does`nt drift offt and ruin You dash.

 

[chengny]

I hear you, but when cutting plastic, it doesn't have that tendency to drift - like you get with sheetrock.

It's actually pretty stable along the line. It's just slow because it gets gummed up alot.

 

[crazy4offroad]

If you use a hole saw, after the drill bit makes its way through, you may want to run it in reverse if the saw teeth are too aggressive and seem like they may have a tendency to chip the ABS.

 

[MrMarty51]

I hear you, but when cutting plastic, it doesn't have that tendency to drift - like you get with sheetrock.

It's actually pretty stable along the line. It's just slow because it gets gummed up alot.

Come to think of it,You are correct,not much thickness in plastic.

 

[82_454_shorty]

Yes, welcome. You've got a black slate there......

Endless opportunities...guy on my K5 forum just make the sickest dash I've ever seen:

That's actually pretty close to what I'm doing.

Thanks for everyone's input. I'll get some pics posted as soon as I get done.

 

[82_454_shorty]

Did my dash this weekend. I'm really happy with the way it turned out.

Took me a few attempts to get the layout centered the way I liked:

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With all of the gauges in:

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And in the truck:

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Thanks for everyone's input on this.

 

[bigtalljohn13]

That looks sharp, where did you get the blank panel from?

 

[MrMarty51]

Nice indeeeedeee,very nice.