DiyMobileAudio.com Car Stereo Forum banner

1 - 20 of 22 Posts

·
Registered
Joined
·
109 Posts
Discussion Starter #1
I have hacked some 8" holes into my door cards and door frame to fit some 8" midbass in there.

Now I'm figuring out how to pretty up the door card sans a tshirt/staples/fiberglass/bondo/27hoursofsanding type of configuration.

The holes aren't perfect, but they're pretty decent and I have some 8" speaker grills in the shed from before. I can make an mdf ring to fit the hole, and a hole in the ring so the speaker grill fits in pretty snug, just need help with something that'll blend the door card and mdf ring, and be able to fill the small gaps.

262174


That's just the ring loosely fitted into the hole, how do I make them 1 and look decent?
 

·
Premium Member
Joined
·
512 Posts
yup hot glue behind them to keep them in place... tape the shit out of front to keep from getting anything on that side... make a milkshake and pour around the back or fiberglass it in from the back...
 

·
Registered
Joined
·
75 Posts
I would use a rigid hard set filler 20/20T. It's a two part epoxy plastic filler used for repairing bumpers. Used it now for close to 20 years and have mastered bonding wooden rings/ baffle plates to interior plastic panels. This stuff is great for bonding, it's strong, and you can feather it in with some skillful sanding and shaping to make it seamlessly blend into whatever panel you are modifying. Just rough up the surface around your ring with 60bgrit paper and put some cuts into it with a razor knife and the stuff will bend like magic...Its my go to product for much of my fab work..Check out my A pillar build which is primarily the result of this filler...
 

·
Registered
Joined
·
109 Posts
Discussion Starter #6
I would use a rigid hard set filler 20/20T. It's a two part epoxy plastic filler used for repairing bumpers. Used it now for close to 20 years and have mastered bonding wooden rings/ baffle plates to interior plastic panels. This stuff is great for bonding, it's strong, and you can feather it in with some skillful sanding and shaping to make it seamlessly blend into whatever panel you are modifying. Just rough up the surface around your ring with 60bgrit paper and put some cuts into it with a razor knife and the stuff will bend like magic...Its my go to product for much of my fab work..Check out my A pillar build which is primarily the result of this filler...
I was gonna sand it and score it so the shake has something to bite into and hold on to.

Do you have a link to a specific product?
 

·
Registered
Joined
·
75 Posts
I was gonna sand it and score it so the shake has something to bite into and hold on to.

Do you have a link to a specific product?
This is what I use commonly. You may be able to source it locally at an automotive paint or body work supplier. There are other products that 3m also makes which are very similar. I've seen some other varieties of this product at places like Oreilly's but holy crap they want a fortune for not very much product. Honestly this product is going to give you more success than trying to bond a polyester based product to that panel. The only polyester based product I've been able to decently blend with plastic panels is duraglas and it's still inferior in my mind to bonding plastic as compared to an epoxy filler like this one....Hope this helps...Any reason btw that you don't want to use .75 plywood? I think it would work better against water and it's just stronger and more durable...
 

·
Registered
Joined
·
109 Posts
Discussion Starter #8
I have epoxy leftover from a countertop I did a few months ago, would that work?

I'm using the mdf as that's what I have, I could get some plywood from HD if it will be that much better. I've always used mdf when doing anything with fiberglass
 

·
Registered
Joined
·
75 Posts
The epoxy resin probably won't work because it doesn't have any additives or filling components. That plastic filler is pretty much a plastic itself you mix up. I just use plywood because too many times I used mdf no matter how I treated it coating it with fiberglass polyester resin or some other product, moisture or humidity always causes the MDF to swell and crumble. Unless you live in California where its dry and sunny year round for the most part the MDF will again eventually fall victim to the moisture effect. A trunk is one thing to have a mdf piece but a car door is a leaky environment. Plywood is just a superior product. I dont use mdf for anything anymore be it a sub enclosure, amp rack, trim panel etc...It would suck to put in that work making the panel look nice only for it to ruin in about a year or two..
 

·
Registered
Joined
·
109 Posts
Discussion Starter #10
I live in Phoenix Arizona, it's rained like 3 times already this year lol. I had tried to put sls 6.5s in the door last year, mounted mdf rings and screwed it into the door metal, ended up making sealed kick pods for them and left the mdf where it was. Opened the door up a couple days ago to being destroying it and the mdf was right there, still stout, had use caulk tape to seal it to the door and had to yank to get it off.

But I get what your saying, and I for sure appreciate the advice. Probably go with plywood from here on out, I just can't get it to cut as clean as the mdf, it chips and flakes and such.
 

·
Registered
Joined
·
75 Posts
I live in Phoenix Arizona, it's rained like 3 times already this year lol. I had tried to put sls 6.5s in the door last year, mounted mdf rings and screwed it into the door metal, ended up making sealed kick pods for them and left the mdf where it was. Opened the door up a couple days ago to being destroying it and the mdf was right there, still stout, had use caulk tape to seal it to the door and had to yank to get it off.

But I get what your saying, and I for sure appreciate the advice. Probably go with plywood from here on out, I just can't get it to cut as clean as the mdf, it chips and flakes and such.
As far as the plywood cutting goes I'm fortunate in that I have a dedicated wood shop ( dust collection, planer, jointer, miter saw, etc). I dont have a premium cabinet saw but still a decent jobsite saw with a sharp blade can make some nice clean cuts. I've been able to make a good bit of furniture and home speakers out of plywood and solid wood from the likes of maple and walnut that would have cost thousands if I had hired someone to make it for me. As far as the advice goes I'm glad to help. I'm getting old these days and like to think I am throwing out good info to people for fab work.

Arizona is beautiful. I would love to drive that Mt. Lemmon scenic highway.
 

Attachments

·
Registered
Joined
·
109 Posts
Discussion Starter #12
As far as the plywood cutting goes I'm fortunate in that I have a dedicated wood shop ( dust collection, planer, jointer, miter saw, etc). I dont have a premium cabinet saw but still a decent jobsite saw with a sharp blade can make some nice clean cuts. I've been able to make a good bit of furniture and home speakers out of plywood and solid wood from the likes of maple and walnut that would have cost thousands if I had hired someone to make it for me. As far as the advice goes I'm glad to help. I'm getting old these days and like to think I am throwing out good info to people for fab work.

Arizona is beautiful. I would love to drive that Mt. Lemmon scenic highway.
Very nice work, looks antique and solid. I've only barely gotten into woodwork, wife wanted a coffee table and it started with making a rustic type coffee table using a kreg jig and circ saw. Definitely isn't a show piece but she loved it. Been doing a little more here and there. Most of my stuff is hand me downs and harbor freight items lol, but they haven't failed me yet, dust collection and planer and things like that are a bonafide luxury to me.

I whipped this up for a mock and I think that's what I'll try to get finalized.
262300

262301


Would the jb weld panel bond 2 part they sell at the depot work?
 

·
Registered
Joined
·
1,506 Posts
First of all you should soak your rings with polyester rezine - this way you will parially protect them from moisture in the doors, and secondly, they will bond MUCH better with fillers and similar stuff. because of that you will not have issues later with seams accuring on the bond between MDF and filler.
It also helps to drill a bunch of holes into the ABS doorcars arround the MDF ring - so the filler will penetrate trough the holes on the other side, thenwhen everything hardens apply filler from the back side too - this way you will create a "sabdwich" of filler/ABS/filler - this is the only way to obtain really good joint between two/three different materials. Polyester and fillers are "chemically similar materials" that will bond good to each other.

Other option is to stack a few MDF/PLY wood rings in a way you can attach that stack to the door metal behind the doorcard and to penetrate trough the doorcard in a way you have ATM. Then just fab a kind of beauty ring that is attached to the doorcard that hold speaker grill and cover at the same time that tiny seam that you have arround the ring/doorcard.... This would be better option for your midbass. This way you will have more solid base for your midbass driver and you will also prevent that drivers play behind the doorcard and make additional buzzing/rattling sounds that you dont want to hear

you can check this thread - Page 2 post 25



 

·
Registered
Joined
·
109 Posts
Discussion Starter #14
First of all you should soak your rings with polyester rezine - this way you will parially protect them from moisture in the doors, and secondly, they will bond MUCH better with fillers and similar stuff. because of that you will not have issues later with seams accuring on the bond between MDF and filler.
It also helps to drill a bunch of holes into the ABS doorcars arround the MDF ring - so the filler will penetrate trough the holes on the other side, thenwhen everything hardens apply filler from the back side too - this way you will create a "sabdwich" of filler/ABS/filler - this is the only way to obtain really good joint between two/three different materials. Polyester and fillers are "chemically similar materials" that will bond good to each other.

Other option is to stack a few MDF/PLY wood rings in a way you can attach that stack to the door metal behind the doorcard and to penetrate trough the doorcard in a way you have ATM. Then just fab a kind of beauty ring that is attached to the doorcard that hold speaker grill and cover at the same time that tiny seam that you have arround the ring/doorcard.... This would be better option for your midbass. This way you will have more solid base for your midbass driver and you will also prevent that drivers play behind the doorcard and make additional buzzing/rattling sounds that you dont want to hear

you can check this thread - Page 2 post 25



I can route some new rings and soak, the ones on the door have been sprayed with truck bed liner already, wouldn't be much fun to remove.

I had wanted to make the speaker flush with the door card but the card slopes so I'd have 1 side out like 3/4" and the other side would be close to flush which would look funky.

In the picture with the grill, the left side of the ring holding the grill is protruding because it's resting against the speaker baffle mounted to the skin and the right side is flush with the skin but has about 1/4" gap of space to the speaker baffle. Was simple going to use some double sided tape and foam to close that gap
 

·
Registered
Joined
·
109 Posts
Discussion Starter #15
The gap on the right is more like .5" while the left is already flush and protruding.
262369
 

·
Registered
Joined
·
1,506 Posts
can you solve this issue some other way - if you look at my picture on post above you can see that I have the in-depth part where speaker sits behind the line of the doorcard, and the louter edge comes directly to the doorcard.... in your case this edge on upper part penetrate over the edge of doorcard. You can solve your problem in a way that you make ring the same way I did and just sand the outher edge so it is flush with your doorcard.

The easyer way is to make kjust a cosmetic mask arround the speaker ring and doorcard - the shape of it could be interesting and good looking, but you will have to reupholster your doorcards

The third way to solve issue is similar as second one - if you look at your first pic posted on 1st post - you can just make a smooth transition from doorcard to the ring and be done
 

·
Registered
Joined
·
109 Posts
Discussion Starter #17
I liked how the ring was flush with the panel on one side and protruding a bit on the other honestly.

I ended up going with that, some sanding and scoring and holes on back side, hotglued the ring into place, milkshaked it and let it set. Then I cut off the hot glue from the front, some more more sanding and scoring, smeared some 2 part epoxy on it, let it set and painted it with more milkshake. Sanded that down, then glazed it.

Don't know if it'll last forever, it did come out the way I wanted it though. Gonna use some berliner for texture, prime it and spray.
262411

262412


I do appreciate y'alls help
 
1 - 20 of 22 Posts
Top