Amp Rack - 1/2" or 3/4" thickness

Going to start on an amp rack this weekend while smoking some pork butts. I am debating on which thickness board to use. I can go with some 1/2" or 3/4" extira MDF.

I think that I am going to thru-bolt the amps. Does it matter what thickness wood that I use?

Personally i wouldn't use MDF at all unless you need to due to exotic shapes or such. I would use HDPE or Starboard or something similar, waterproof. When i did the current boat i used Alucabond which is 1/8" thick and rigid as sin. Doesn't move at all and is very light and waterproof. 1/16" HDPE covered by a sheet of aluminum 1/32" thick on both sides.

Yeah but HDPE is not exactly cheap.

No it's not J.Brenner, but then how big is the amp rack? Large sheets are expensive but smaller pieces aren't bad. Also if you search around you can find cheaper sources for it.

MDF is less than ideal unless you want to coat it in fiberglass, then it would be ok. Just use marine grade plywood and maybe a clear penatrating epoxy sealant. Unless you plan on sinking the boat you should be fine for many, many years.

Have you ever about Extira??? Look it up?

I may do King Starboard. Can I get away with 1/2"

Murph 1/2" birch plywood is cheap and will do you good.

I think that I am going to go with some 1/2" EXTIRA MDF. It is a water resistant MDF. For added insurance I will roll a coat of epoxy resin over the wood pieces.

I can get a sheet for about $45 here in town.

I used marine grade MDF but honestly the likely hood of any real problems is poor. Their gonna be mounted where there is little moisture if any. If they get wet you have a lot bigger problems than the wood.

+1 for what hatepain said

You guys worry about the amp rack getting wet and MDF not holding up... if you amp rack gets wet, then your amps are most likely getting wet.

I've always used MDF and then carpeted it afterwards. I also keep them suspended from the floor, in case any water did roll through the storage its not going to get the rack & amp wet. No problems ever...

Just get a bog cutting board from walmart or somewhere and mount to that. You can cover it with carpet if you want. That way no wood no rot. I mounted my amps to one and also my onboard battery charger. I will post a pic in a minute.

MDF is very susceptible to high humidity levels, not just direct water contact. My little workshop is not sealed and climate controlled. If I dont use up all the MDF board in a couple months, it's done. It will begin to swell. If you go with wood, even marine plywood, i'd seal it.

cutting board. I just used the bolts that were already there from the bow seats to mount it.

Hey guys - I'm gonna chime in on from an electronics manufacturer point of view. We can debate best materials until we see cows flying...Everyone's got a good point and something that has worked (or not) in the past. I see more and more people picking up those monster cutting boards from costco, chopping them down and mounting product on them as (Adam) has.

But lets not loose track of the real question here: Is it splashed water or is it moisture that does the damage? Usually its the latter that destroys an enclosure over time. We all know that if you toss water on electronics or the amp rack wood they are mounted to, you will have problems. (pain said this well - your going to have bigger issues than the enclosure). But assuming for a moment that's not going to happen (we all hope) the reality in the marine environment is that your fighting moisture on a daily basis. To be specific, what I'm talking about is when the sun goes down and comes back up in the next morning creating that dew factor when your out on the lake or parked in your driveway. When this happens (and it will), this condensation will penetrate from the just about everything not sealed and work its way out as the water tries to evaporate along with the atmospheric pressure changes (sung comes up). This is what turns nice shiny amplifiers into "Chia pets". This is what rots wood --- everyone with me?

So my 2 cents is get away from mdf, its only asking for trouble. If money is the issue, ask yourself how much you spent on the boat to begin with and the amplifiers and stereo going into it cost ya. I suspect that taking the high road will pay off in the long run. And if money is still the issue, head to Coscto or Walmart and shop the kitchen aisle. Really!

peace

-Brian
Exile Audio

I just used 1/2" MDF and then painted two coats of herculiner (from checkers autoparts). Herculiner is actually salt proof!! Nothing is going to get thru herculiner. However, a small can of herculiner is $40 and 4X8 sheet of MDF is about $26. I could have saved myself tons of money if I just used one of those cutting boards.

I am mouting three amps. The cutting board is not big enough.

I am going to use birch and seal it with epoxy resin. I have never had a problem with it before and boat is stored in a very nice enclosed garage.

Thanks for everyones opinion

What about Lexan?

I forgot about lexan. The amp that is on the drivers side in my supra is mounted on lexan. Here is a pic of it. This pick only shows some of it. It is the amp on the left side of the picture. If you would like a better picture of it let me know. The amp behind the sub is for the tower speakers and it is mounted to a cutting board.

You can rest a resin-coated MDF enclosure in a pan of water continuously for days without any apparent seam separation or resin blistering. But once you dry it out and get it wet again, just watch how the damage accelerates with each wet/dry cycle.

MDF enclosures begin to expand and decompose from the bottom up. The cause is primarily those few rollers that momentarily leave standing water everywhere.

Resin-coating an MDF enclosure can provide reasonable protection for multiple seasons if the enclosure is elevated off the deck and definitely off any carpeted surface. A resin-coated enclosure can shed water without damage if you plan for drainage. But if you sit the enclosure into a moisture and mildew trap, with time it will certainly wick up moisture through any and all coatings.

Gelcoat is tough stuff but will crack on every seam and grow blisters when applied to micro-porous and water-soluable MDF.

In fact, MDF is not airtight. You can easily pull vacuum or push compressed air through MDF from the cut edge to cut edge. This is why changes in humidity will eventually cause all water-soluable materials to fail in a boat. MDF or a solvent-based fiberboard, like MEDEX for example, make for better box building that is understandable.

But for an amp panel, I would highly discourage the use of MDF, in any form. I like the way screws bite into a solvent-based birch plywood, especially when its 3/4-inch thick. HDPE, ABS or KingStarboard get really expensive in the thicker versions. You can use a polyester resin but epoxy resin is better. The cut edges of any material is the biggest concern so elevate the amp panel off the floor with polymer strips or pads. Also, space the amp panel off the hull so that water can freely drain behind it versus getting trapped and eventually absorbed. This space can also serve as a concealed wiring raceway.

Cover the amp panel in a marine-grade non-mildew rubber-backed carpet. Stay away from automotive trunk liners and carpet. If you're really picky, you can silicon the carpet edges and silicon over staples and silicon fill pilot holes. Your amp panel should outlast the boat.

For protection of your amplifiers and other electronics, install drain tubes from overhead drink holders into the bilge. And if your bilge air vents passing through the deck cap are a source of incoming water then carpet this too.

Do not use MDF. Anything would be better than MDF. No matter how you seal it. I've been using wide trex to mount mine. It's cheap and has held up great.

And to anybody who doesn't think the amps get wet from the moisture/humidity in the boat, you're nuts, mine are almost always drenched all summer, I took the PCBs out when I got them and conformal coated them though so no worries.

stupid question. where do I get "cutting board"?

^^ at walmart in the cutting board isle. maybe by the kitchen stuff and the knifes