Guide A mission in mesh - modding a grille into your bezel.

Whilst starting my recent case project, to house an internal watercooled system inside a Cheiftec Dragon, I decided to fit two 120mm fans inside the front bezel.

To do this meant that I had to cut away the centre section to allow them clearance.

I had originally planned to cover the resulting gap with a speaker grill or perhaps some fine alum mesh but then I was sent a couple of samples of modder's mesh to work with by Bill Owen (mnpctech).
This turned out to be better than anything I think I could have found on my own.


After I modded the mesh into my bezel, I kept being asked how I had done it and even whether I was willing to do it on commission for others.

Well, I hadn't taken any photos of the process at the time but after it was so well received, I decided to repeat the mod in the top half and take pics along the way.

This would hopefully enable people to do it themselves rather than pay me to do it (as if I have the time).


The Chieftec door is a good example to work with as we will cover three different edge mating techniques.

If your desired application is of a different construction you should still be able to apply whichever combination of techniques best suits it.


Part 1 - Shaping the mesh.

I'll assume you'll have cut the centre out of the door and read mnpctech's guide to working with mesh and can already have your mesh cut oversize with a straight fold on each side, together with a light overall curve, so I'll start from there.

Pics are clickable for larger ones.


One piece of mesh, lightly curved with edges folded and trimmed to the required depth to sit in the recess left after cutting out the centre panel.


The all important test-fit.
After each stage you carry out, check that the mesh still fits as intended.
This will hopefully prevent any single mistake from being compounded.
Fingers crossed, eh?


If you're doing the top and bottom as I've done here, getting both parts to line up completely may be a little challenging but the extra effort is definitely rewarded if you can pull it off.


Woohoo! ... err, I mean here we observe the results of careful planning.
It's not like anyone will ever take a ruler to it but it is more obvious when the holes don't line up properly.


Going in close, you can see the excess that you could simply trim off but we'll be using it to create extra rigidity to allow for the fact that we've cut out a fair bit of structure from the door.


Mark into tabs two or three cells wide and cut away.

Next, turn the piece over and mark off the point where the tabs overlap.


I find a planishing hammer perfect for this job but a hammer's a hammer, so use whatever you have.
Knock over each tab in turn about 20 - 30° and move on to the next tab along.


Allow the hammer to strike against the surface beneath for a sharper line rather than just on the overhanging mesh.
Once you've gone all the way along, come back to the start and chase over each tab by the same amount again.
Lather, rinse, repeat.


Flatten out any kinks you've made in the face itself and on the lip, not forgetting to check regularly that the shape of the curve still matches that of the bezel.


Push it up against the end and once the fit is good, mark off the vestigial cells to be trimmed away.


Once the excess is gone, it begins to fit like it's meant to.

Check the other side for a flush fit that follows the contour of the whole piece.


The reason we didn't just start with the tabs this size is that the extra cells help keep the shape better until after the desired fold is achieved.
Leave the tabs longer if you have the space to do so.


The bottom part required a double-curved shoulder.
This was acheived by a 90° fold made in the same way as the top section, then simply putting the grille in place and folding the tabs down and back against the plastic of the door.


The shaped piece, ready to be test-fitted.


Stage one complete. =]

Part two - Moulding it in.
[Coming soon]


Thanks go out to mnpctech for donating the mesh and adwhitworth for hosting the pics.

 

wow...

i think i may do this mod as well gives it a very nice industrial look i like it a lot good job

btw:
http://www.adwhitworth.co.uk/Pug/pics/overlap.jpg
cut your finger or something? looks like blood.

 

does indeed look kind of blood like... Can I get that stuff at any hardware store? Would probably look better on my server case than the sucky grille it has now....

 

looks kinda like the new apple case

 

Re: wow...

Cheers guys. I've moulded it in now but my replacement HDD turned up on Friday, so I spent the weekend rebuilding my rigs and need to get all the photos together for uploading.

Heh, there's a clue in the upper left corner of that pic...

As it happens, that was a bad idea to use a CD pen, as the celllulose primer let the ink bleed through.
Better to use a scribe or maybe a chinagraph pencil for marking out.

RAMeLaiR - I can get some in for people from mnpctech if there's enough interest, it sounds like people are having a hard time finding it elsewhere in this thickness.

Seth - haven't seen the apple case but did have heard it compared to the Chieftec Matrix before now...


I'll be priming today with any luck - I found some plastic filler primer at Halfords yesterday.
Trouble is, I could only find the plastic primers they do in 300ml cans - the 500ml would have been nicer at only a quid more.

I need to do some more moulding on the middle bit for the switchgear and have a new idea for something I want to do in the door (need some narrow C-section) but I'll try and get some more pics up later anyhow.

 

Right, update time.


First the door, rubbed down with various grades of wet/dry flatting paper - 240grit will take off the paint and factory orange peel followed by 400 grit to smooth out any sanding imperfections (actually, I probably started with 1/4 of a sheet of 180 and kept using the same piece till it almost wore out but still... you didn't read that).
Although it's not as obvious in the pic, the grooves are well sanded this time to avoid the crack I got from a lack of a key to the surface in the first stage of the project.


Stage one of trying to be too clever - I decided to prime before filling to ensure best coverage of the different primer types I was using.
I sprayed the mesh with etch primer and the door with plastic primer.
Then I remembered that filler doesn't always like lying on primer - fortunately I got away with it but you should probably miss this stage and just mask off well later on.


Crap idea number two. Couple of g-clamps, wood, a mousemat and the waxy sheet left from some tractor-feed printer labels (to stop the resin sticking).

I thought "I know... I'll brace the front and fill from the back - lots of time and effort saved when sanding down".
Well, I couldn't have been more wrong. Bear with me and you'll see but for now - leave this step out too.


Tools of the trade. I haven't got a roller wheel for smoothing out the air bubbles, otherwise there would be one in the shot too. Also missing is the lump hammer I use for cleaning my brushes when there's no acetone to hand.

This is where it all started to go horribly pear-shaped for a while.
Basically, it might have been alright if I'd used something a little more substantial than a mousemat to clamp with.
I mixed up my resin and went to tack the mesh in place by just painting over where it met the door and working it in between with the brush.
I went down one side, then the other before I noticed that the grille wasn't sitting flush in the hole!
Aargh!
The resin was starting to set, so I finished off as best I could and picked up the piece to squeeze it into place with my hands for ten minutes, while it hardened.

Unfortunately, I pressed a little too hard at the top, meaning I had to sand away a large portion of the door to get it to meet smoothly.
Worse than that though, the sticker backing worked so well at not having the resin stick to it, it ran all over it and stuck to the front of the mesh instead.
I must have individually hand filed at least a third of the bloody holes on the thing after that, if not more by the end of it.

Right, now that I've got that out of the way, back to the bit where I didn't **** up so much...


Having decided to say "bollocks!" to the fibreglass mat and resin for the time being. I decided to use the fibreglass-based Isopon P40 bridging filler as it would achieve a similar result in the grand scale of things.
I used the narrow black applicator to apply it and the white one to mix up on.


Golf ball and a pea measured by eye, and away we go.


As you can see, the gloves from the earlier pic fit me so well, you'd almost think I wasn't wearing any... and the angle the photo is taken from, nearly makes it seem like the mask is on top of my head instead of over my face. *whistles unconvincingly*
Scraping a small amount onto your applicator at a time, press it into place and push out any possible air bubbles with the end of the card.
Don't worry too much if the fibres stick out here and there, you can sand them down easily later.

Ok, that was one side. A quick check to make sure nothing's popped out of place, then turn it back and carry on with the other side, followed by the top and bottom.

Make sure you turn the piece over and smooth the other side down a bit if you can. It will save time later and help ensure that you don't have air gaps in crucial places.
(You can see where the resin went wrong earlier here too)


Tada! Step back and marvel at how the mess you've created could ever possibly look like anything but ****e again.

Turn it over, hmm, looks a little better. Not much though.

Hmm, "bleeding gums" Murphy comes to mind.
(aargh! the swear filter ate my thumbnail url [link works though], I knew I should have called it shte, too)



Time for a clean up.

 

Some time later...


The front looks slightly more respectable. You can see though, it's not there yet.


As does the back now (well, it will be seen when the door is open and so needs a bit more attention than the lower bezel did).


Same technique. Here I wanted to fill the two lower channels and give a bit of body to the door to bring it out a little further to match my lower piece.


Here, I've just gone around filling the gaps left from earlier.




For the next indeterminate period of time, I sat with a pack of diamond files and an array of diamond dremel bits, grinding away until I heard the tone changed pitch, indicating that I was through the resin and back to bare metal, then consequently moving on to the next hole.

I spent so long on this part, I nearly forgot to take pics again when I moved on to the next stage.




Using the same technique as with the heavier weight filler, I hit it with the aluminium based stuff.
Lightweight modern fillers are so easy to sand, you can go quite thick but you should always build up in thinner layers unless you know from experience exactly what thickness you can get away with.


A few hours more sanding makes it look almost good enough for a test fit, so here goes...


Happy with it? If so, now it is time to prime (not earlier as mentioned ).

I masked off the plastic to etch prime the mesh first, as the plastic primer should coat the plastic, filler and etch primer equally well.


Suitably attired (except for the shades) and ready to paint, I move out to the garge for painting.
The mask in my left hand is the one I use for dust based stuff like rubbing down, the cartridge one I'm wearing is preferable for the primer in my right (airfed respirators are only really necessary for isocyanate based chassis paints, not normal aerosol based stuff, so don't worry if you only have one of the ones shown).
Keep your painting area well ventilated and don't spend too long in it at a time.



Couple of tips for keeping the dust off your work -
Hose the floor down if you can. A finger over the end of the hose to produce a fine mist, sprayed through the air will settle any dust for long enough to keep it off your piece when spraying.
If you're spraying a metal piece, ground it with a earth strap made from a piece of wire and a crocodile clip or similar (in an inconspicuous place) to stop static from attracting any remaining dust.




Mesh primed and tape removed. As you can see, I overlapped the filler slightly.
This is okay - it could be feathered back if necessary but I'll be laying down more coats of primer than a Ferrari has paint, so you won't see a ridge or anything.

Back out to the garage for a coat of plastic primer or three.
Don't worry if you don't have complete coverage straight off. Keep your coats even and not too thick.

Once the primer is done, the smaller imperfections will become apparent (pits and scratches).
Leave it to cure in a warm place for a day or two,then it's time to break out the stopper (cellulose putty).
You can do this stage before priming too, in fact it's probably better to but I'm like that for conventional practice...



After sanding this back, you can think about hitting it with hi-build (filler) primer and so on to paint.




If your paint skills are okay, it should hopefully look something like this after priming & rubbing down correctly.



I'll be doing a bit of fibreglassing to it again soon, if you want to check it out as an optional alternative to the heavyweight filler - keep an eye on my HexaDragon thread.
Good luck with it, if you try it.

 

Looks like a factory finish... good work!

 

Very nice! Question though... Would either JB Weld or Bondo work for this as well? I've never used this Isopon P40 bridging filler you talk about and am hesitant to use a fiberglass based product.

 

Cheers guys.

Atomic - I was kinda hoping it was better than the crap most factories turn out.

j/k Ta!
[Edit] BTW, that's only the primer stage, I haven't painted, clearcoated or polished it yet.


Dad - JBweld might do it, it seems to do just about anything - but you might find it more of a pain to sand.

Bondo is like a lightweight filler and may crack with flexing (which is inevitable when you fit the bezel).
It's ok for filling dents but the fibres really help with the bridging and fixing part.

Bondo's ok for finishing off but there are better products afaik.
That said, there's only one way to find out.
I just used what was available to me that I knew was good for the chosen application (can't get Bondo over here).

 

Hello

Pictures will be backup hopefully in a few hours. My host has decided they want to upgrade to Plesk 6 and are taking an awfully long time about it. I can't wait till the year is up

 

I might just have to use this u know

 

Hey cool. My thread got blessed.
Thanks, your eminence.

J/k. - If I missed anything out, let me know.
For the main materials (thought I'd listed 'em), I had really good results with Isopon P40 for the heavyweight filler and was really impressed with their Metalik for the lightweight stuff.
The etch primer was U-Pol Acid Etch #8.
The rest you can find easily at any motor factors or auto paint specialists.

FWIW - Apparently Bill's been getting a few UK enquiries for the mesh, so he's going to ship me a bunch of pieces to cut down on individual shipping costs.
Should be in stock in a few weeks.

 

That is SO tidy! As you know, I like a clean mod... and that is clean!

 

Good work pug
Are you able to get any modders mesh in? Im havent been able to find any uk suppliers yet

 

Damn that looks ILL.

Modders mesh is on my shopping list now

 

Cheers guys.

Yeah, the first batch should be here in a week or two (along with a sidepanel for my new project that Bill's waterjet cutting for me )

 

how much would you be charging abouts?

 

That looks a fantastic, gonna have to use that in one of my mods /me thinks.

Great spray job also bud


Carl

 

Cheers carloshax - I hope the paint and clearcoat can come out with the same quality.
I've had a few probs with the cellulose stopper shrinking and have been using polyester based stuff since.
Also got some wrinkling on the bezel where I got impatient when I was painting too late in the day.
A lesson in patience, methinks.

Shogun - price will be as close to mnpctech as I can get.
Sizes outside 1' x 1' and 1' x 2' will need ordering in specially though, as those are all I'll get to start with.
I've been talked into getting round hole as well as the hex stuff (we're looking at getting it in Alu as well as the 22 guage steel too) after someone checked out halfords and they only do much bigger hole stuff for car grilles and all that.