It has a very thin consistency, that of water almost, and absorbs immediately. I've applied one coat to some scrap but i'm not sure it's enough, especially on the end grain.
Yes it's very thin. I just slapped as much as possible on in one go. Come back over it again later whilst it's still 'wet' and slap some more on. Use a good, wide deep, real bristle brush and don't worry about making a mess as you will have to sand it all anyway.
You could try two coats, but I think the idea is to do it in one go so it's uniform/singular through the material.
You could try two coats, but I think the idea is to do it in one go so it's uniform/singular through the material.
pinkmouse said:
It sounds more like this stuff we get in the US. Minwax wood hardener. It's used to repair rotted wood before applying a filler.
"Minwax® High Performance Wood Hardener's extra hard resin is dissolved in a solution of solvents. These solvents carry the resin deep into the pores of the wood where they quickly evaporate leaving behind the hardened resin resulting in hardened wood."
An externally hosted image should be here but it was not working when we last tested it.
http://minwax.com/products/woodmaint/hardener.cfm
Vikash,
I applied around 5 coats of the stuff when I did it, apply liberally and leave for 5 minutes, come back and do again until you get a glossy film buildup which means that the MDF can't suck up any more. After that leave it overnight and then sand it back once the resin is formed and hardened.
The ends on MDF soak up loads of this stuff - I used a single tin just on one of the satallites for the Perceive v2.0's!
After you've sanded it all back, you'll have a lovely smooth surface to work with and spraying is an absolute pleasure after this. You can literally treat it like car body work with only a few coats required rather than 10+ with lots of sanding as before without the hardener. I also expect that the wood hardener has a positive effect on the stiffness of the MDF and hence maybe the sound? This is unfounded but I can't see it harming anything but rather helping.
I applied around 5 coats of the stuff when I did it, apply liberally and leave for 5 minutes, come back and do again until you get a glossy film buildup which means that the MDF can't suck up any more. After that leave it overnight and then sand it back once the resin is formed and hardened.
The ends on MDF soak up loads of this stuff - I used a single tin just on one of the satallites for the Perceive v2.0's!
After you've sanded it all back, you'll have a lovely smooth surface to work with and spraying is an absolute pleasure after this. You can literally treat it like car body work with only a few coats required rather than 10+ with lots of sanding as before without the hardener. I also expect that the wood hardener has a positive effect on the stiffness of the MDF and hence maybe the sound? This is unfounded but I can't see it harming anything but rather helping.
People might find these emails between myself and Ronseal interesting, particularly the comment on usage from Ronseal.
richie00boy said:
Rich,
How many folks spray their speakers? How many of these speakers have joints effected.
Solvents are in the paints used for spraying and in potentially more volatile forms too. Never have I heard anyone complain of joints loosening or speaker falling apart because of this.
For a test on just how irrelevant the issue is; spread a thin coat of wood adhesive onto a scrap peice of MDF, let that dry for 24hrs and then apply a few coats of the hardener. You'll quickly see that what happens is that there's zero reaction and the wood hardener simply fails to penetrate the wood because of the glue.
BTW: I use that Bonda stuff from the link on the first post of this thread as well as Evostik Resin W Weatherproof wood glue as shown here:
http://www.axminster.co.uk/sfile/1/jump/0/product-Evo-stik-Resin-W-Weather-Proof-22031.htm
I thought I highlighted it, but maybe I wasn't clear enough 🙂
Was my point. I don't know what the issue is, but the makers should know a thing or two about using the product. I appreciate you use the Bonda stuff but I would imagine it's basically the same.
Was my point. I don't know what the issue is, but the makers should know a thing or two about using the product. I appreciate you use the Bonda stuff but I would imagine it's basically the same.
richie00boy said:
Whilst I can't give a definitive answer its likely that its simply because of health and safety issue's.
The stuff is poisonous and treating anything that isn't rotting (ie. outdoors) is likely to mean its inside or in regular contact with people.
Seriously, there is zero and I mean zero negative effects with this stuff. The only thing that doesn't look great is the fact that it turns the MDF a nasty looking brown colour but that doesn't matter once you've sprayed the stuff, here's a shot to illustrate that fact:
An externally hosted image should be here but it was not working when we last tested it.
That's an early shot of the speakers I'm working on and they've been in a similar state for around 3 months now. Nothing untowards has happened and the primer on the satallite isn't flaking off etc.
As far as I'm concerned its doing what I wanted it to with no ill effects.
Why not just ask them to elaborate why it "should not be used as a surface coating" instead of beating around the bush?
That's what I've asked them. But being Friday afternoon I didn't expect a response just yet. Just thought I'd post up in case somebody else was aware of some issue, and in case people were thinking of using it this weekend.
I suspect the agent you spoke to was just reading from a scripted reply, and doesn't have that much in depth knowledge. There may well be some specific issues involved, but to make things straightforward for the customer services staff, the technical department have probably just issued a blanket "don't do it"
Why not plain old polyester resin?
High build, so I can't imagine more than two coats being needed to give a very sandable plastic coating to work with.
And rather than endless multiple coats, just sand and polish to your liking.
High build, so I can't imagine more than two coats being needed to give a very sandable plastic coating to work with.
And rather than endless multiple coats, just sand and polish to your liking.
noah katz said:
The Bonda stuff I use is a polyester resin, or at least that's what it says on the tin.
Eitherway it works, saves me time and materials and the net result is I'm happy with it.
Just try the stuff out on some scrap MDF you've glued together - if your happy, great, if your not don't use it.
"should not be used as a surface coating"
Shin isn't using it as a surface coating. He's letting it soak in and harden the MDF, which is a little better structurally than rotten wood but not much. 😉
Shin isn't using it as a surface coating. He's letting it soak in and harden the MDF, which is a little better structurally than rotten wood but not much. 😉
No magic bullet for your problem.
Ed gave the best advice. Instead of butt joining your boxes glue them up with mitred joints.
MDF is prposely created with a more dense outer layer and a less dense core. It absorbes finish an MOISTURE differently in the core than at the outsides. Moisture is you real problem. And all your truly wonderfull work on the exterior of the box is for nott if you don't seal the interior of the box to.
Hope this helps!
Mark
Ed gave the best advice. Instead of butt joining your boxes glue them up with mitred joints.
MDF is prposely created with a more dense outer layer and a less dense core. It absorbes finish an MOISTURE differently in the core than at the outsides. Moisture is you real problem. And all your truly wonderfull work on the exterior of the box is for nott if you don't seal the interior of the box to.
Hope this helps!
Mark
Re: No magic bullet for your problem.
I agree about sealing the innards.
Its a habbit I picked up from the car audio days and now carry on through to my home projects too. It definitely helped with the car audio since its exposed to damp and the elements in general but in the home it may be considered non-essential but it doesn't hurt eitherway.
There's also the trick of skinning the outer layer of the cabinets with 9mm MDF so as to cover up the the unwanted joints and then you bevel the edges of this skin to mate with the rest of cabinet. In practice what you then have is a joint right on the corner of the bevel and it looks completely natural/seamless.
mwmkravchenko said:
I agree about sealing the innards.
Its a habbit I picked up from the car audio days and now carry on through to my home projects too. It definitely helped with the car audio since its exposed to damp and the elements in general but in the home it may be considered non-essential but it doesn't hurt eitherway.
There's also the trick of skinning the outer layer of the cabinets with 9mm MDF so as to cover up the the unwanted joints and then you bevel the edges of this skin to mate with the rest of cabinet. In practice what you then have is a joint right on the corner of the bevel and it looks completely natural/seamless.
Thank You, Mark
We have many resources and methods from which to choose. It will, in the end, come down to what the individual is willing to invest in their project. Not a small part of that being their own effort. Sealing the interior of a cabinet can be accomplished with ANY vapor barrier. That may be a mess of glue, paint, sealer, part of a constrained layer dampening scheme.....
For some, it comes down to working with the materials at hand, with entirely satisfactory results.
I'm more of the ANALytical mode, I'm interested in the best it can be, don't tell me it can't be done, (so, why not?) school. I work every day to avoid pushing that on someone from another school. I learn in the process.....
There have been some good products brought to light here.....ones that I think I can use in projects having nothing to do with speakers. I'll file them away, but not out of reach.
We have many resources and methods from which to choose. It will, in the end, come down to what the individual is willing to invest in their project. Not a small part of that being their own effort. Sealing the interior of a cabinet can be accomplished with ANY vapor barrier. That may be a mess of glue, paint, sealer, part of a constrained layer dampening scheme.....
For some, it comes down to working with the materials at hand, with entirely satisfactory results.
I'm more of the ANALytical mode, I'm interested in the best it can be, don't tell me it can't be done, (so, why not?) school. I work every day to avoid pushing that on someone from another school. I learn in the process.....
There have been some good products brought to light here.....ones that I think I can use in projects having nothing to do with speakers. I'll file them away, but not out of reach.
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