How to attach aluminum to HDPE?

[1cargarage]

Hello all,

I have designed a plier rack for my toolbox that will be constructed out of 3/32" sheet aluminum, which will act as the tool dividers, and 1/2" High Density Polyethylene (HDPE), which will act as the backing plate. The backing plate will be screwed to the front of the drawer from the sides and bottom of the drawer so that the screws will be hidden.

As of right now, my plan is to use my table saw to cut dados along the HDPE strip 1/4" deep using a 3/32" kerf blade. In the back of each partition along the HDPE backing plate, I am also planning on plunge routing 1/2" wide circular recesses and inserting neodymium magnets at the appropriate height of each plier handle to keep the pliers from sliding forward when the drawer is closed.

My question: Does anybody know an effective way to attach, chemically or mechanically, the 3/32" sheet aluminum dividers to the 1/2" HDPE backing plate in the dado grooves?

I cannot screw the aluminum to the HDPE because it is too thin, and no glue that I know of bonds aluminum to HDPE.

Thanks in advance

 

[rsanter]

Make little tabs or pins coming out of the aluminum
Drill holes in the right place in the dato
Insert metal and bend over tabs

Bob

 

[Capt Chrysler]

Silicone will stick to some HDPE. What type do you have?

Capt. Chrysler

 

[phill u7c]

Try DP490 glue, takes about 12 hours to fully cure, but man it will stick diamonds to grease!!!

 

[EdT]

There are adhesives that are made to stick to HDPE, but they are pretty expensive and come in a dual syringe that requires you to get a special gun and some static mixers. Probably something north of $100 for 1.7OZ tube ready to go. Not the solution I'd pick for the project at hand. Other alternatives might be to run a couple of,say, #6 all-thread tie rods form one end to the other tying the HDPE blocks together. You might be able to cut into the end that goes into the dado and bend out a small 1/4" square tab through which a screw could be driven into the HDPE. You wouldn't have to do every one, just a couple would suffice. Bending the aluminum at a tight enough radius would be dicey especially if it's 6061-T6. You should anneal it locally if you want to try that approach. Possibly you could put the aluminum on a soft surface like a wood block and knock some bumps into it with a center punch. These would deform the HDPE when assembled, but because it's HDPE, it would probably flow back around the bumps over time. Similar to above, you could form some tiny louvres in the aluminum that would interfere with the slots. You could lose the HDPE and make the ends out of something easier to stick to. Aluminum comes to mind. Then you could just do a tack weld on the underside and you're done.

 

[1cargarage]

Silicone will stick to some HDPE. What type do you have?

Capt. Chrysler

I haven't bought the HDPE yet because it is pretty expensive to custom order dimensional blocks from tapplastics.com. I was considering "King Starboard" because it comes in colors other than the standard opaque white. The other option I was considering was to get a commercial cutting board (opaque white) and just section that. Any thoughts?

There are adhesives that are made to stick to HDPE, but they are pretty expensive and come in a dual syringe that requires you to get a special gun and some static mixers. Probably something north of $100 for 1.7OZ tube ready to go. Not the solution I'd pick for the project at hand. Other alternatives might be to run a couple of,say, #6 all-thread tie rods form one end to the other tying the HDPE blocks together. You might be able to cut into the end that goes into the dado and bend out a small 1/4" square tab through which a screw could be driven into the HDPE. You wouldn't have to do every one, just a couple would suffice. Bending the aluminum at a tight enough radius would be dicey especially if it's 6061-T6. You should anneal it locally if you want to try that approach. Possibly you could put the aluminum on a soft surface like a wood block and knock some bumps into it with a center punch. These would deform the HDPE when assembled, but because it's HDPE, it would probably flow back around the bumps over time. Similar to above, you could form some tiny louvres in the aluminum that would interfere with the slots. You could lose the HDPE and make the ends out of something easier to stick to. Aluminum comes to mind. Then you could just do a tack weld on the underside and you're done.

Wow, thank you for the suggestions. As for the 'expensive' adhesives, Google has shown me a few that look promising (some from 3M and LocTite), but like you said, the prices are north of reasonable.

As far as the all thread option goes, that sounds reasonable, but I do not have a drill press and I would prefer to keep the backing plate to 1 piece. Perhaps I could cut the aluminum dividers so that they had a tab at the bottom that extended the full 1/2" of the HDPE backing plate and rabbet the bottom of the HDPE so that the aluminum tabs were exposed. By doing this, I would eliminate the need to section the HDPE into individual blocks, and because the HDPE left from the rabbet would act as the stop for the all thread running through the aluminum, I wouldn't actually even need to use all thread. I could use basic bar stock or even a wooden dowel. GENIUS!

Thank you so much. I will be sure to post pictures whenever this project makes it to the top of my to-do-list.

 

[EdT]

You could just put an aluminum plate on the bottom to tie it all together. You could put stopped slots in the end pieces and drop the long aluminum pieces in from the bottom and then put a plate on the bottom to tie it all together. You could use aluminum angle suitably notched and screwed to the bottom of the blocks. You could get some scrap corain or other composite counter top material for almost nothing and use it instead of the HDPE. Works well with carbide wood working tools and you can paint it any color you like.

 

[theoldwizard1]

I was considering "King Starboard" because it comes in colors other than the standard opaque white.

Good stuff. Not cheap. Google "Starboard adhesive"

The other option I was considering was to get a commercial cutting board (opaque white) and just section that. Any thoughts?

Actually a good alternative where looks are not the first priority. Big Lots or a Dollar Store.

Mechanical fastening is probably the best. Stainless wood screws, through bolt or rivets.

 

[kerrynzl]

Urethane adhesive. It needs to remain flexible to bond the HDPE

 

[Capt Chrysler]

If the HDPE is slick feeling it has a form of "slip" add to it when it was manufactured. The slip adds a surface lubrication to the material. This type of HDPE is not made to be bonded.


Capt. Chyrsler

 

[paranoid56]

hey op, what are you trying to make with HDPE? i deal with it a lot and there are some local dealers that have it for not that bad of price, or if you need a smaller scrap piece i could probably find some laying around.

as for gluing i have no idea, as nothing i have found (thats cheap) works

 

[1cargarage]

hey op, what are you trying to make with HDPE? i deal with it a lot and there are some local dealers that have it for not that bad of price, or if you need a smaller scrap piece i could probably find some laying around.

as for gluing i have no idea, as nothing i have found (thats cheap) works

I see you're in SD. What part? I'm in Pt. Loma. I'd be willing to meet up and pick your brain about working with HDPE since I have no experience working with it.

Here is a rough drawing of the top view of the plier rack that I want to build. The drawing only shows 6 dividers and 7 compartments, but essentially, the HDPE would span the entire width of the drawer and as many metal dividers as necessary would be used.

Top View: (NOT TO SCALE)



The blue lines are the 3/32" aluminum/steel dividers between which pliers will be stored standing on end.

The yellow highlighter section is the 1/2" HDPE. As you can see in the picture, I would just dado the grooves into the HDPE on my table saw 1/4" deep.

I only drew one magnet, but they would be in each plier's partition in the actual plier rack.

If both materials were wood, I would run a little carpenter's glue in the dado, set in the dividers and call it good. In this situation however, I don't know of a reasonably priced adhesive that would accomplish this. Hope this clears up the ambiguity of what it is I'm imagining. Thanks in advance.

 

[mike13u]

If you used a 1/4" of HDPE in front and 1/4" in the back, you wouldn't need a way to attach the dividers you could sandwich them using the drawer dimensions and avoid the mess. You would have the same amount of usable space for pliers as well. Cut your Dados 1/8" deep. You could still use 1/8 or 1/16 thick round neodymium magnets pressed into a flat drilled holes using a forstner drill bit.
Doing it this way would also prevent you from having to screw through the sides of your drawer. I think it would look cleaner overall too (at least it would in the back of the box).

Also, those little coin size neodymium magnets they sell on amazon are SUPER powerful. You would only need one to hold that little rack to the front wall of drawer. If your ****, maybe one front and one back if you did it the way I described above.

 

[1cargarage]

If you used a 1/4" of HDPE in front and 1/4" in the back, you wouldn't need a way to attach the dividers you could sandwich them using the drawer dimensions and avoid the mess. You would have the same amount of usable space for pliers as well. Cut your Dados 1/8" deep. You could still use 1/8 or 1/16 thick round neodymium magnets pressed into a flat drilled holes using a forstner drill bit.
Doing it this way would also prevent you from having to screw through the sides of your drawer. I think it would look cleaner overall too (at least it would in the back of the box).

Also, those little coin size neodymium magnets they sell on amazon are SUPER powerful. You would only need one to hold that little rack to the front wall of drawer. If your ****, maybe one front and one back if you did it the way I described above.

Thanks for the input. The neodynium magnets are mainly for holding the pliers to the back of the rack / front of the drawer. Currently, every time I shut my plier drawer all the tools slide forward ~1" and it's pretty annoying. I would bore the hole for the magnets from the back of the plier rack so that the magnetic force would be pulling through the leftover thickness of the HDPE.

 

[N.I.]

Just glue them in with a good epoxy.

I have experimented in the past bonding PE. It is surprising how strong a good mechanical bond can be. From your drawing it looks like you have a good bonding surface area.

Preparation is key. Roughen up the end of the aluminium using course sandpaper and make sure everything is clean.

I doubt you are going to be swinging or jumping up and down on a pliers rack.

 

[EdT]

WRT the magnets. That'll work Ok for the intended purpose, but you will probably pay for it with slightly magnetized pliers. Depending on what kind of work you are doing, this can be a problem. I do a lot of metal fab and magnetized tools are a PITA because they end up looking like fur balls from picking up chips, grinding dust etc..

 

[er3456df]

According to your drawn plans:
Dove tail the plastic.
saw tooth the end of the aluminum for fitment in to the dovetail.
slip saw toothed and set/bent "teeth" into the dove tail.
Now the aluminum are removable and adjustable. The degree of tooth set determines the fitment strength.

I like this. Wouldn't even need a true dovetail, just a burr on one side of the aluminum, hammered into the slot from above.

 

[Dustball]

Scotch-Weld DP 8010 or Loctite 3030 should be the adhesives you want-

http://www.shop3m.com/3m-scotch-weld-structural-plastic-adhesive-dp8010-off-white-35-ml.html

http://www.henkelna.com/product-search-1554.htm?nodeid=8797903290369

 

[1cargarage]

WRT the magnets. That'll work Ok for the intended purpose, but you will probably pay for it with slightly magnetized pliers. Depending on what kind of work you are doing, this can be a problem. I do a lot of metal fab and magnetized tools are a PITA because they end up looking like fur balls from picking up chips, grinding dust etc..

Good point. I'll keep that in mind. I don't think it will be much of an issue for me though because this will be for my home box, and I don't do much metalworking at home. I usually stick to automotive and woodworking. Thanks for the tip

I like this. Wouldn't even need a true dovetail, just a burr on one side of the aluminum, hammered into the slot from above.

Both are good suggestions for a mechanical bond. Thanks guys.

Scotch-Weld DP 8010 or Loctite 3030 should be the adhesives you want-

http://www.shop3m.com/3m-scotch-weld-structural-plastic-adhesive-dp8010-off-white-35-ml.html

http://www.henkelna.com/product-search-1554.htm?nodeid=8797903290369

I will look into these as well. Thank you Dustball

 

[paranoid56]

i am in the mira mesa area. i would just add another hdpe part just like you have in the back of the drawer to capture the other side of the alu dividers. since its whole drawer you shouldn't need more than 1 magnet on each side, and if cut right you might not even need those.