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Discussion Starter · #1 · (Edited)
I got yesterday a car audio empty 4/5mm MDF box for a 10" driver and am going to use it in my home theater set up with a dayton reference high fidelity driver RSS265HF-4.
I am so happy with the build quality it is rigid and heavy as all car boxes should be and will strip it from its carpeting.
The port will do it myself and tune the box around 24Hz and in room-FR should go down to 20Hz in just 42liters/1.5cf volume :hsd:

I know a lot of you guys have done very beautiful projects and wanted to ask you what is the best way to have a nice satin black..what primer underneath is better oil or water based. Which is the better way to apply the paint in terms of quality - spray or roller..
I am not afraid i can do wrong because i know i can sand it back down. Thanx for any help
 

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Discussion Starter · #3 · (Edited)
The box is (30x40x60)cm or (1x1.3x2)foot or 1.5 cubic foot inner volume.

Here what i got from WinISD



I get for the port 3inch (7,5cm) dia 18inch(18)inch long. I didnt go with a larger port because I am going to use this 175W amp from hypex:



A tune at Fs of the driver 26Hz seems to provide more natural FR:



i got this output as SPL at 175Watts:



And here is the box i got from amazon:



The original ports yields a curve with a bump on the FR around 50Hz..:bigsmile:typical car audio stuff :




I am going to glue another MDF plate on top of the front one to seal the slot port, get a tune I prefer with variation of the port length (a simple PVC tube from the local store) and also protect the speaker suspension. For the port I'm going to direct it downwards.
The cabinets look like awesome with an extra MDF... if i get close to this project in terms of painting that would be perfect :innocent: it is from caminoguy



Source:
http://www.hometheatershack.com/for...ts/24825-shiva-x2-passive-radiator-build.html
 

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Did you take account for driver displacement in that 1.5 ft^3 ? As far as a black satin finish I paint cars for a living so my way of doing it may be a little to involved and expensive but I would try something like a kilz oil based primer about 3 coats. Sand that down real smooth and try to get something like rust o leum in a quart and try to roll it on in smooth coats till it's completely covered. Like I said though thin smooth coats so the texture doesn't get gloppy. If you have any other questions about the finish let me know I'll try to help you the best I can.
 

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Discussion Starter · #5 ·
Thank you Jstslamd so much for your ideas. Yeah i took into consideration the driver displacement but not the amp, but it is small.
I found the Kilz and the Rust-Oleum in the internet but i couldn't find them here i forgot to tell you i am from germany.

I was off today at a local OBI store (i dont know if there are some in US but it is a huge store ) and took advise from a guy who showed me a 2-component "very hard, like wood" Putty from Molto, do you think i can rely on it?
Then I asked him to give me advice on a primmer, i explained him it will be for MDF and he showed me a pre-varnish (primer and varnish in one without color) i dont know how to say that in english and a spray mat-black with protection against scratches. But i was suspicious about the sprays whether they'd do the job.

After that I came across an attractive woman.. she was the chief of a big department with paints varnisches and so forth and showed me two products. Bevor that i asked her about the paints for metal and she said they were all acrylic or water based and in terms of endurance she showed me these which suppose to be better:

1) Primer from XT series Alpina, extreme one even on rusty surfaces, here is the link:
http://www.alpina-farben.de/portal/...564/tabid__575/Alpina_XT_Vorstreichfarbe.aspx

2) Paint which was a silk-matt black, extreme scratch and shock/hit resistant (that is the translation below the label)
http://www.alpina-farben.de/portal/productid__4567/back__564/tabid__575/Alpina_XT_Buntlack.aspx

3) A roller to apply the paint it was a very fine "bubble free" sponge

Kunstharz on the pictures means synthetic resin. It says also it lasts for 10 years.

How do you think those will work? Do i need to use also a clear coat or enamel on top of these?

I need to do a hard work now on pulling of the carpeting, make a whole below for the port and for the Hypex plate amp. I will post photos as i proceed
 

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Discussion Starter · #6 · (Edited)
I stripped it from the carpetting, it took like 30 minutes and was more difficult than i expexted with these spots :dizzy: It looks not easy here and i have no idea how to handle it, i will try with sand paper.
It needs a good amount of putty also.



 

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Do you have access to a air driven dual action sander or atleast a palm sander ? If so get something like 40 grit sand paper and sand it smooth. The glue on ther may actually help fill the pores a little bit which would mean less priming.
 

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Discussion Starter · #8 ·
I am going to rent an air driven dual action sander and the router for the openings from the obi store. There is a carpentry service inside as well so i will get the front mdf-plank from there :T.

Do you think the primer and the paint+varnish will do good, otherwise if you know an international brand i can search for it? I am not afraid even if it gets a bit more expensive
 

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The only European brand I can thing of off the top of my head would be a company called akzo Nobel it is actually the paint bran we use at work. If you buy something from them try to track down there sign paint line which is called grip gard. Let's back up a second here though. As long as your primer has adhesion to the wood and the paint has adhesion to re primer and you are getting the desired look from that paint then that paint will do fine. At the
Store just ask the people in the paint department if these two product are compatible together if so then it will do fine. Just make sure that your prime and prep job is spot on as that is the bones of the whole paint job. After that the paint job will be cake.
 

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Discussion Starter · #10 · (Edited)
There is a problem .. I am in the middle of cutting the baffle for the speaker with the router and as i move the bit the wood is burning :huh: with a lot of smoke, can anyone help? I am using a bit for metals..i thought it shouldnt be that different from the woodworking
 

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Discussion Starter · #12 · (Edited)
Thank you Jstslamd for helping me with this, i am ok with simulation, driver parameters and building custom amps but when it comes to carpentry and finishing this forum and the help from you guys really means a lot.

I couldn find dual induction sander, nevertheless I sanded it with a conventional one Grid 40, it helped to remove only the upper threads from the carpeting.

On the upper left corner is what it looks like after sanding, and in the middle a spot i treated with an wire-tearing accessory for the driller, because sanding didnt help on the deeper level:




This is the accessory for the driller, it gets stuck because the carpet turns into molten plastic :no: and bonds with the tool and with the MDF:




Here is what it looks limke after treating it with the drill maschine accessory after 5 hours work:




When i try harder to tear the remaining spots then a molten material comes from my tool and gets spread over the MDF, i couldnt do it bettter. Anyway the surface is pretty even, now the question is whether this could form a solid base for the primer and the whole painting
 

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Have you tried to buzz over the box again with the sander after all of the carpet was removed? If the glue is still of it's not a good idea to just cover it up as the surface will never get hard. A belt sander may also be a good tool to help strip off the remaining glue. You should be able to rent one of those from your local hardware store. Let me know how you make out.
 

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Discussion Starter · #14 ·
Yeah i tried afterwards buzzing and pressing up on it, different moving patterns and pressures on the tool but it doesnt help a bit.. those remaining spots are extremely rigid, they get removed only when got molten. I tried even with a very heavy and rough file like 3 punds heyvy but it tears absolutely nothing from it. It is like my box is protected from a shield and the only tool that helps, the drill accessory, now is full of it and now functions like a depot for this synthetic material. I will try with a belt sander maybe the high speed will get it molten. Besides the 40 Grid sand paper gets also stuck with it while removing the upper layers but only when molted and doesnt help at all for removing the deeper ones. May be it is necessary something more radical to tear this away.
 

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There is so much material impregnated (carpet fiber, some seriously heavy duty industrial adhesive) that I am personally going to tell you to:

1. Throw the box away
2. 'TRY' and cover it with 5/8's MDF and wood screws. Basically sleeve the box in MDF.
 

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Discussion Starter · #17 · (Edited)
Thank you for your advice Jstslamd, i did some work recently and when it is not going to work i am seriously considering your first option(throwing away :)) or veneering it. I also bought the primer and the paint so i waste a bit from the primer to see how it tolerates the spots, they are pretty smooth on the touch though..

My first real world experience with the router.. I am ready with the baffle for the front plank it worked like a charm with the wood bit, the pivot doesnt move at all. Also the opening for the plate amp worked fine, it is perfect rounded rectangle, i didnt know i can this :dontknow:. I am finished with the putty as well, i will post new photos tonight. I may waste the primer on this but at least i will give it a try. And than when it is not working i am really considering your three options.
Greets and many thanx
 

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Discussion Starter · #19 · (Edited)
I sanded the putty and glued the front, here are some photos from today

On the tiny dots i'll put some putty as well











it will soon come clear whether its going to work or not
I need to put some more putty on the seams of the new plank, sand it and try the primer, i'll post photos as i progress
 
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