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getting a xover board out?


TimmyTonga

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As in one that is both stapled and glued, like in this 3a Improved

AR-3a imp2 xover.jpg

 

Can this be done successfully? Is it just a matter of painstakingly removing the staples, and then trying to lever up the board?

I want to move nice boards into nicer cabs.....

Any tips gratefully received.

Tim

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Having recently removed a pair of boards from AR-3a's, I can say that Carl's method works very well if the glue has dried out; one board came loose with no problem (the color of the original adhesive was black), the other was a living hell to get out (yellow glue), resulting in numerous scraped knuckles, and an afternoon of frustration.

Have you thought about installing new boards in the nice cabinets?

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I'll give the putty knife a go and see how I get on. I think cutting out the back is also worth considering - the nasty cabs are pretty nasty. You've still got to get the boards off, but at least not through the woofer hole....

I'd like to keep the old boards if I can

thanks 

tim

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On 8 November 2016 at 11:53 PM, ar_pro said:

Having recently removed a pair of boards from AR-3a's, I can say that Carl's method works very well if the glue has dried out; one board came loose with no problem (the color of the original adhesive was black), the other was a living hell to get out (yellow glue), resulting in numerous scraped knuckles, and an afternoon of frustration.

Have you thought about installing new boards in the nice cabinets?

Got the good boards out of the bad cabs (I cut the back out like genek suggested) but the bad boards seem to be stuck down into the good cabs with......yellow glue. Snipped all the components off to give me more space to work and taken all the staples out but nothing I've tried seems to work with this stuff (various scrapers and levers, hot air gun). I don't see how I can avoid removing it, as placing the good board on top of it would mean my binding posts and tweeter energy switch would be too recessed.

ar_pro, did you find any techniques that got you anywhere? 

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31 minutes ago, TimmyTonga said:

I think it is. But you can't really get enough heat on it to melt it because the board acts as such a good insulator.

Dribble some isopropanol on it and let it soak and soften the glue. Don't use too much. A small pipette will aid in applying the solvent. The older hot melt doesn't soften as quickly as the newer hot melt.

5-ml-disposable-pipette-for-essential-oi

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DavidR's suggestion would definitely be the one to use first.

Alternatively, I've found that smacking the end of a short piece of 2x4 with a hammer against the binding post panel could knock the whole board loose.

This is not guaranteed - you might just wind up with a circular piece of masonite lying in the bottom of the cabinet.

I wound up chipping & chiseling the masonite board away with a variety of sharp implements, and it was a miserable experience.

Good luck, and let us know how things go!

 

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Thanks to you both for your suggestions. I'm pretty sure what I have as a board is not what you call masonite; it certainly isn't the same stuff that the surround gets attached to in a speaker basket. Being made in the UK, they used a UK equivalent we call hardboard, and it doesn't hold up well when exposed to liquids. I'm going to score the surface with a craft knife and then sponge it with hot water. I suspect it will turn to an unappetising sludgey goo, which will then reveal the surface of the glue for treatment.

But actually I suspect I will get up tomorrow and try the 4x2 plan first, as I couldn't possibly turn down the opportunity of a quick fix....and I don't think there's a downside. Suspect however, that as hardboard is less strong than Masonite, I will just go straight through it.

we shall see!

t

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What we often refer to as Masonite (the creator of this manufacturing process had the surname Mason) is merely a proprietary name for hardboard, but yes, exposure to moisture should generally be kept to a minimum - - - hence, the pipette for careful application, I suspect. But the first step should definitely be careful removal of the staples. 

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I have used a dental pick type tool to lift the staples slightly and then yank them out with needle nose pliers.  When I want to control the amount of solvent applied I use a insulin syringe. This works especially well when removing dust caps.  Most AR crossover boards I have run across have virtually fell out after the staples were removed, but I suspect that glue was pretty much dried up.

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4 hours ago, ar_pro said:

Yes, be sure to get all of the staples out.

As for the hammer and 2x4 - my advice is to not be shy; hit it like you mean it!

Maybe freeze it first to make the adhesive more brittle ;)

There always seems to be one or more staples that you didn't see.

Barring this you can keep working a flexible blade around the perimeter until the seal breaks.

If you are in a hurry you will break the boards but then you weren't planning on saving these anyway.

Roger

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I have never removed one but one thing I would try after removing staples is using a Dremel with a flat metal blade or even a flat fine wood blade. Would work the edges and just cut through the glue.

Other alternative is heating a three inch drywall blade to red hot status and working it through the glue by gloved hand....or tapping it with small hammer.

To clarify....this Dremel.......

 

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I popped the boards out of my 58S', which were held in the same way.  a very stiff putty knife, and careful prying, and they popped right out.  the glue was dry and hard, and came with the board.

 

when I reinstalled, I used clear silicone and some short screws.

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With the white glue the boards popped straight off after removing the staples (sorry about the blur)white glue.jpg

The yellow glue just isn't that co-operative;

yellow board snipped.jpg

but I took inspiration from all suggestions - thanks to everyone for chipping in. 

 

2x2 and sledge - before.jpg

 

2x2 and sledge - after.jpg

Unfortunately, as was predicted;

sledge result.jpg

But knocking out that hole is crucial, as it gives you a point to work from which is not right next to a vertical. You can work outwards from the hole;

boardscrape 1.jpg

I soaked the board in near-boiling water with a sponge, and then used a heat-gun and paint-scraper. The water is important because not only softens the hardboard, but it helps conduct the heat down to the glue;

boardscrape2.jpg

Took about an hour once I got the plan established. The mid-unit hole is really useful for sticking your arm through to get at it from another angle.

xo board gone.jpg

 

It would have been impossible to have removed them without total destruction, so I'm lucky that the crossovers that I wanted were stuck down with white glue and the ones I didn't with yellow, and not the other way round.

Given that the 3a Improved has a a lot of components on the board, having it outside the cab for assessment and possible upgrading is really handy, and I'll screw it back when finished in case of further tweaks.

Tim

 

 

 

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1 hour ago, ar_pro said:

All right! That's a nice job in a difficult space.

Will you be able to fit a drill/driver into the areas where you'll put screws?

I hadn't thought that far ahead : )

but now I am thinking about it the answer is probably no.

not made easier by the board being crammed with components, which limits options

If I was a Dremel-owner I would probably have an attachment that drilled at right-angles.......

 

 

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