DTSFab.com (Desert, Trail and Sand)

The Machine Shop => Everything Fabrication => Topic started by: Enemy on February 27, 2016, 08:12:51 PM

Title: Molding and gluing ABS plastics
Post by: Enemy on February 27, 2016, 08:12:51 PM
I need to modify a heat/ac plenum box on the firewall of a Ranger to gain some exhaust clearance and am trying to figure out the best way to do this..
Currently what I have is a factory AC plenum. Since I have deleted the AC system, I am just cutting this box down so I can get the air plumbed back into the truck. Non-AC air plenums have all but disappeared, so got to work with it.
I have not worked much with plastics as far as molding and bonding. Just years of painting the shit lol. So any advice, video and supply links, or pics you may have (FABR!) would be greatly appreciated to get me going. Or even if I should work with an entirely different plastic altogether, I'm all ears!
 Here is a couple vids I watched so far trying to get a basic idea of the process..
http://www.youtube.com/watch?v=3BdFAv0nHCo (http://www.youtube.com/watch?v=3BdFAv0nHCo)

Kinda wanted to punch this guy before I got through the entire vid, but some good ideas..http://www.youtube.com/watch?v=71v186sokFE (http://www.youtube.com/watch?v=71v186sokFE)
Title: Re: Molding and gluing ABS plastics
Post by: fabr on February 27, 2016, 11:22:58 PM
Have you read my posts showing/explaining how to di it yet?
Title: Re: Molding and gluing ABS plastics
Post by: Enemy on February 28, 2016, 08:12:44 AM
I dug through your build posts, but am having a hell of a time finding it. I thought this is the process you used for building the duct work for the AC in the desert car correct?
Title: Re: Molding and gluing ABS plastics
Post by: fabr on February 28, 2016, 09:00:12 AM
Ya ,I can't find it either. Must have been lost during one of the sites eff ups. Anyway,,,,,,,those vids are pretty lame. The first one is useless for our discussion. The second one has a couple good pointers as to bending/cutting the stuff. It is really very easy to heat and bend the stuff.

The abs"glue" is done best,IMO,using small chips of abs no larger than 1/4" size (I prefer using the very small chips I reclaim from sawing the stuff on the table saw. I just run a piece thru the saw and gather up the chips,easy and quick.) I put the chips into a cheap ass condiment dispenser(preferrably clear) like the ketchup and mustard bottles at the burger joint with the spout on top. They are poly and not affected by acetone. Fill the bottle maybe 1/2 full with the chips and add enough acetone to cover them. Sit back for a few hours/overnite and all the abs chips will be dissolved. Stir the slurry well.Add acetone to the slurry to make the consistency needed. If you already had it too thin ,either add more chips or just let it sit open and evap some acetone off. I like it about the consistency of very thick pancake syrup +/- depending on need.

I usually prep outside corner joints needing glued with offsets so I can fill it with the slurry/glue. I prefer a fairly thick slurry that when dispensed thru the spout in the condiment bottle will give me a nice joint just like it was welded. It actually is welded-solvent welded.A thicker slurry will flow to a very nice fillet on inside corners. Outside corners will be nicely rounded.

One tip is to make abs chips from the actual abs sheet you are fabbing from. It will be an exact color match ,same exact properties as the surrounding pieces,and will make a  joint as strong as the parent material.

 You can make the slurry any consistency you wish to suit your needs but remember the joint will take a few hours to fully harden,just like working with plastic model cars and such.Once fully hardened the joint is 100% as strong as the parent material. Just like welding metals together. Just imagine the spout on the condiment bottle being your mig gun. 
Title: Re: Molding and gluing ABS plastics
Post by: sandracer1 on February 29, 2016, 06:45:39 PM
They make some really good plastic epoxy's. I used some from Advanced Auto Parts to repair a broken Plastic vacuum fitting in an old Mazda I had. It was super tough and withstood the direct engine temps for years. 2 part and cheap. If it is a butt joint it should hold up well based on my experience. They also make plastic welders if you have extra $$$$. They work well also.
Title: Re: Molding and gluing ABS plastics
Post by: fabr on February 29, 2016, 06:56:07 PM
With ABS plastic there is no better/permanent/stronger way than solvent welding it as described above. Other plastics are a whole different story.
Title: Re: Molding and gluing ABS plastics
Post by: fabr on February 29, 2016, 07:04:02 PM
Enemy,I just noticed you said it was going to be near the exhaust. If that is so,ABS is not a good choice of material as it is pretty easily softened with heat. Approx 235 is the vacuum forming temperature. For hvac duct like I did it is perfect but near an exhaust? I doubt it.
Title: Re: Molding and gluing ABS plastics
Post by: Carlriddle on March 01, 2016, 05:27:12 AM
My guess it close to the turbo manifold up pipe area.  Definitely some foil insulation or something like it?  Otherwise it will feel like you always have the heat on, even if the box don't melt!!

And I saw some pics of Enemy's new convertable, sweet!!  rofl 
Title: Re: Molding and gluing ABS plastics
Post by: Enemy on March 01, 2016, 10:28:16 AM
It will have a good sized air gap away from the wrapped downpipe and will also be a heat shield layered on top of that just in case. Also plan to use 1/8" ABS if I can find a good source for the stuff. After a hard 25psi pull radiant heat in the area is minimal. "Should" be fine  :k
If not I will go back to my ole reliable backup.. Aluminum

And I saw some pics of Enemy's new convertable, sweet!!  rofl 

I  am just now looking at those Carl! DS definitely went to town on the cage last night!!
Title: Re: Molding and gluing ABS plastics
Post by: fabr on March 01, 2016, 11:47:23 AM
Aw,I really like the modified upper cage.
Title: Re: Molding and gluing ABS plastics
Post by: fabr on March 01, 2016, 11:48:38 AM
1/8th " is what I'd use as well.
Title: Re: Molding and gluing ABS plastics
Post by: Carlriddle on March 01, 2016, 02:39:52 PM
Ps, dont leave stuff unattended in DS's garage.  Especially if hes got Jack out there.  LMAO
Title: Re: Molding and gluing ABS plastics
Post by: dsrace on March 01, 2016, 03:40:12 PM
stop it there was only 1 jd and coke in my garage during the unpeeling   ;D ;)
Title: Re: Molding and gluing ABS plastics
Post by: Enemy on March 08, 2016, 09:00:09 PM
Got er done!
Thanks for the write-up Fabr! Everything worked out really good!
This is a great material to work with, easy to shape cut and bond. We got some more ideas brewing for the future with ABS for sure. I used 1/8" which is about the equivalent of the oem air box. I test bonded a few pieces of the old box to the new stuff and it melted together quite well as long as I got the paint and last 25 year of road grime off.

The original Ac box with the evap core removed
(https://dtsfab.com/proxy.php?request=http%3A%2F%2Fi516.photobucket.com%2Falbums%2Fu329%2Fbeerfarm1%2F1988%2520Ranger%25202_3Turbo%2FIMG_2172_zpshdm0bya8.jpg&hash=ad72dff6b21fd3cf28184c4c40c5eabe95a79ea9) (http://s516.photobucket.com/user/beerfarm1/media/1988%20Ranger%202_3Turbo/IMG_2172_zpshdm0bya8.jpg.html)

 (https://dtsfab.com/proxy.php?request=http%3A%2F%2Fi516.photobucket.com%2Falbums%2Fu329%2Fbeerfarm1%2F1988%2520Ranger%25202_3Turbo%2FIMG_2173_zpsqz6c2cyh.jpg&hash=1d314319587eeaea2889c5afbf04ead8915e843e) (http://s516.photobucket.com/user/beerfarm1/media/1988%20Ranger%202_3Turbo/IMG_2173_zpsqz6c2cyh.jpg.html)

(https://dtsfab.com/proxy.php?request=http%3A%2F%2Fi516.photobucket.com%2Falbums%2Fu329%2Fbeerfarm1%2F1988%2520Ranger%25202_3Turbo%2FIMG_2182_zpsr0eh62hv.jpg&hash=20776e4f207f02e58e0337aeb834ecd8d7a82332) (http://s516.photobucket.com/user/beerfarm1/media/1988%20Ranger%202_3Turbo/IMG_2182_zpsr0eh62hv.jpg.html)

(https://dtsfab.com/proxy.php?request=http%3A%2F%2Fi516.photobucket.com%2Falbums%2Fu329%2Fbeerfarm1%2F1988%2520Ranger%25202_3Turbo%2FIMG_2183_zpskbsvctrp.jpg&hash=cc4e1e0b52201a419dd0392d01a04eec24309d2a) (http://s516.photobucket.com/user/beerfarm1/media/1988%20Ranger%202_3Turbo/IMG_2183_zpskbsvctrp.jpg.html)

(https://dtsfab.com/proxy.php?request=http%3A%2F%2Fi516.photobucket.com%2Falbums%2Fu329%2Fbeerfarm1%2F1988%2520Ranger%25202_3Turbo%2FIMG_2185_zpsctej2gfy.jpg&hash=2fa2d678d311ed9c8af58d8edcbc3f97967c0bbe) (http://s516.photobucket.com/user/beerfarm1/media/1988%20Ranger%202_3Turbo/IMG_2185_zpsctej2gfy.jpg.html)

Added a layer of heat shield then shot some SC804 flat black over the whole box just to guinea pig the stuff lol. It hasn't come off the cylinder head at the exhaust ports yet so should be good.
(https://dtsfab.com/proxy.php?request=http%3A%2F%2Fi516.photobucket.com%2Falbums%2Fu329%2Fbeerfarm1%2F1988%2520Ranger%25202_3Turbo%2F34bcd83e-68e6-41a6-ad0e-61fbdf4427ad_zpssanswlh7.jpg&hash=4a340e1a229f0a9f3fc69c0bc3a9c3f796b5c8c4) (http://s516.photobucket.com/user/beerfarm1/media/1988%20Ranger%202_3Turbo/34bcd83e-68e6-41a6-ad0e-61fbdf4427ad_zpssanswlh7.jpg.html)

One piece and goes into place really easy with a couple inches of clearance to the downpipe. Hopefully it does the job!
(https://dtsfab.com/proxy.php?request=http%3A%2F%2Fi516.photobucket.com%2Falbums%2Fu329%2Fbeerfarm1%2F1988%2520Ranger%25202_3Turbo%2FIMG_2193_zps4m2ms8bq.jpg&hash=1651631d0733991371a2f4f8dd42227dc2906cb0) (http://s516.photobucket.com/user/beerfarm1/media/1988%20Ranger%202_3Turbo/IMG_2193_zps4m2ms8bq.jpg.html)
Title: Re: Molding and gluing ABS plastics
Post by: fabr on March 08, 2016, 10:00:17 PM
Well,ain't that purty!! Nice job! Ya,I have a few pieces to fab last thing around the front lights and hood nose.  Have you tried your hand at heat forming it yet?
Title: Re: Molding and gluing ABS plastics
Post by: Carlriddle on March 09, 2016, 05:35:56 AM
Model cars for grown ups!!  Came out slick.

Title: Re: Molding and gluing ABS plastics
Post by: fabr on March 09, 2016, 05:54:46 AM
I don't know about that grown up comment....................... ;D ;D ;D
Title: Re: Molding and gluing ABS plastics
Post by: Enemy on March 09, 2016, 07:35:42 AM
I don't know about that grown up comment....................... ;D ;D ;D
I don't either. Please explain in further detail please.  rofl

The only heat forming I used was on the flat under the shield to get the contour right, and get a bit more clearance. Easy to get carried away with the heat, that's for sure! Going to take some more practice to get the hang of that.
Title: Re: Molding and gluing ABS plastics
Post by: Carlriddle on March 09, 2016, 07:54:29 AM
For older kids.  Same as buggies, model cars for grown up. rofl
Title: Re: Molding and gluing ABS plastics
Post by: fabr on March 09, 2016, 09:38:12 AM
I'm still a kid.
Title: Re: Molding and gluing ABS plastics
Post by: dsrace on March 10, 2016, 02:57:11 PM
you are fabr and there is one even bigger kid and his name is fast!!!!  rofl

i'll have to stop by enemy's to check out his work and mooch a xx beer lol
Title: Re: Molding and gluing ABS plastics
Post by: Enemy on March 10, 2016, 05:40:54 PM
Hell yea! Always got a couple frosting up!
SimplePortal 2.3.7 © 2008-2024, SimplePortal