yes damar thing is Therebent solvant. That said there are some water solvant products that are more toxic than some ancient features with alcohol/therebent/petrol solvants... I always work outside with any of them. I have done some veenering refurbishing on a mate speaker and a speaker of mine due to the lock down those last days. Dust is tricky outside but health diserves it.
I only heard Feastrex once during an extended listening session. I concur with your assessment.
White glue is similar to ModPodge (both PVA), but dries more flexibly. I wonder if the added ingrediants help with that. Certainly more water than i use to thin it (and that changes as the consistency of what is left in the container tends to dry out a bit as it sits (and more of the container is empty).
dave
dave
Sounds like the ModPodge gets really hard? If I understand you correctly, it dries harder than the white wood glue?
The white wood glue I usually use for speaker cabinets dries to a hardness similar to flexible plastic. That is a lot harder than I was thinking to use for damping.
I also don't think it would stick well to rubber surrounds.. drips can generally be scraped off 'sealed' surfaces, seems it needs to be soaked in to the wood (or other materials) a little bit to really 'grip'.
The white wood glue I usually use for speaker cabinets dries to a hardness similar to flexible plastic. That is a lot harder than I was thinking to use for damping.
I also don't think it would stick well to rubber surrounds.. drips can generally be scraped off 'sealed' surfaces, seems it needs to be soaked in to the wood (or other materials) a little bit to really 'grip'.
It gets hard but remains flexible. That flexibility is important. Adding more coats does stiffen things up, and i have, with some woofers, used multiple coats and some with decreasing radius to stiffen the inside of the cone more than the outside making for more controlled dispersion and roll-off up top (but less extension). The woofers in question were being crossed low.
This is an example:
7” SDX7 driver has an (unusual) woven cone on a sealed substrate. The loose fibres can vibrate. The yellow is stock, the red is 3 coats of thiined modpodge in decreasing amounts that tie all the fibres together. one can see a significant flattening of the top end and making the roll-off much better giving an effective extra octave of usable extension at the top.
dave
This is an example:
7” SDX7 driver has an (unusual) woven cone on a sealed substrate. The loose fibres can vibrate. The yellow is stock, the red is 3 coats of thiined modpodge in decreasing amounts that tie all the fibres together. one can see a significant flattening of the top end and making the roll-off much better giving an effective extra octave of usable extension at the top.
dave
Attachments
I have rarely used it on rubber surrounds but it does stick.
I have also used it to replace the coating on old KEF B110/B200 when the existing coating has peeled off, so it sticks to bextrene as well.
dave
B200 had many iterations : bextrene, paper (coated ?) I don't think about B200 paper coating but some coatings on paper indeed can not be seen), foam surrounds, rubber suround, inverted rubber surround...
On the B200 iir, the front paper cone had litlle honeycomb or little micro excavations... while the back was raw as a paper with loosy fibers in it - sort of at eyes but only made of paper -
If I sumarize :
- from the edge of the surround, aka interface between the suround and the cone :
add a circa 5 mm/1/4" layer of half hard coating : to break the upper pick one can see sometimes on some frequency curves. If paper this tacky thingy may enter the paper. Should we coat the two sides when the surround is sandwiching the cone.
- coating the whole cone is about getting more pistonic behavior but still has to stay loosy not to create such picks as aluminium drivers typically show.
- the back of the cone should be more tacky than the front cone. The front cone having less deep coating - lighter- : a good way is the varnish used for classical furnitures varnishing called also english varnish. Made from vegetable or animal material in solvant : that stick on all material (irons too) with very thin layers as asiatic lacquer work.
- eventually this thin layer(s) can be the substract of something thicker/harder/smoother according the targett. I.E. : Dave pattern seen above on a Fostex "Zig two way" tacky thin glue or Poodge on a layer of thin damar coating in order to isolate the inner paper material to drink it.
-or draw like ScanSpeak (Illuminator, Revelator lines - but which are more 3D material work as well like excavations r "extravations")
-if the hardness of a coating is apllied : it has to come loosier when going towards the center of the cone. The mushroom center should stay lousy though !
The conversation extented on coatings but still in the topic as it's about to supress peaks or breaking modes of the cone.
If not too much off topic please : is there something we should know about the way to layer it ? like furnitures makers, i.e. without paintbrush but more spray or pads ?
I saw also ruber conpounds for foam surround in order to increase their lifespan but does it not change the Qm by hardening and weight too much such foams (Seas A25 10" speaker driver coes in mind)
Is there a cnsensus about tweeter domes please ? readed an old post where Sy was giving a bath receip for silk domes with "rat paper glue. traps" à la Dynaudio/Morel - which should be more acrylic receips for these brands of course.
On the B200 iir, the front paper cone had litlle honeycomb or little micro excavations... while the back was raw as a paper with loosy fibers in it - sort of at eyes but only made of paper -
If I sumarize :
- from the edge of the surround, aka interface between the suround and the cone :
add a circa 5 mm/1/4" layer of half hard coating : to break the upper pick one can see sometimes on some frequency curves. If paper this tacky thingy may enter the paper. Should we coat the two sides when the surround is sandwiching the cone.
- coating the whole cone is about getting more pistonic behavior but still has to stay loosy not to create such picks as aluminium drivers typically show.
- the back of the cone should be more tacky than the front cone. The front cone having less deep coating - lighter- : a good way is the varnish used for classical furnitures varnishing called also english varnish. Made from vegetable or animal material in solvant : that stick on all material (irons too) with very thin layers as asiatic lacquer work.
- eventually this thin layer(s) can be the substract of something thicker/harder/smoother according the targett. I.E. : Dave pattern seen above on a Fostex "Zig two way" tacky thin glue or Poodge on a layer of thin damar coating in order to isolate the inner paper material to drink it.
-or draw like ScanSpeak (Illuminator, Revelator lines - but which are more 3D material work as well like excavations r "extravations")
-if the hardness of a coating is apllied : it has to come loosier when going towards the center of the cone. The mushroom center should stay lousy though !
The conversation extented on coatings but still in the topic as it's about to supress peaks or breaking modes of the cone.
If not too much off topic please : is there something we should know about the way to layer it ? like furnitures makers, i.e. without paintbrush but more spray or pads ?
I saw also ruber conpounds for foam surround in order to increase their lifespan but does it not change the Qm by hardening and weight too much such foams (Seas A25 10" speaker driver coes in mind)
Is there a cnsensus about tweeter domes please ? readed an old post where Sy was giving a bath receip for silk domes with "rat paper glue. traps" à la Dynaudio/Morel - which should be more acrylic receips for these brands of course.
Sorry. The ones i refer to are the ones that were commonly available for DIY (and the few larger magnet variations i have gone thru that were in there’s, or a few other boxes.
Mostly B200 SP1014
TL Links
By picks do you mean resonanant peaks?
dave
I have only used modPodge to replace the coating already on when it started peeling off.
I scored a set of boxes with 4 B200 SP1014 in each (free :^), and they still sit outside under the deck. When the rain is heavy the cones start turning white as they absorb water. Goes away when things dry out. I expectthat this is what contributes to peeling.
The drivers are currently trapped as the 8&^% T-Nuts have come unseated from the back of the MDF baffles.
dave
ahaha nice story 
!
Definitly have to try ModPoodge, Zig, thank you...
for the shellacs I have already some unwaxed clear type from India for furnitures refurbishing so sort of damar but meaty (from insect) not vegy.
Brits have a good feeling with plastic cone material and mid frequencies... I assume they took a lot of Seas or Vifa drivers off the shelves if not doing their own mid drivers...
! Definitly have to try ModPoodge, Zig, thank you...
for the shellacs I have already some unwaxed clear type from India for furnitures refurbishing so sort of damar but meaty (from insect) not vegy.
Brits have a good feeling with plastic cone material and mid frequencies... I assume they took a lot of Seas or Vifa drivers off the shelves if not doing their own mid drivers...
One of the materials that came to mind is actually Butyl Rubber, the stuff that is used for gloves, roof sealant etc. Perhaps its a blend of butyl rubber and something like LeakSeal®.
My thoughts about Butyl Rubber is simply that since the cone and surround is introducing mechanical shock to the material, it might not be enough that it has the properties of an elastomer, but also need to remain tacky while elastic to aid in substrate bonding.
If one want to try these materials, paper is not the only material of interest since there are a handful Al cone drivers that would be interesting to experiment with.
Butyl rubber - Wikipedia
My 2 cents
My thoughts about Butyl Rubber is simply that since the cone and surround is introducing mechanical shock to the material, it might not be enough that it has the properties of an elastomer, but also need to remain tacky while elastic to aid in substrate bonding.
If one want to try these materials, paper is not the only material of interest since there are a handful Al cone drivers that would be interesting to experiment with.
Butyl rubber - Wikipedia
My 2 cents
Waterproof PVA does resist water much more, but it s characteristics may differ.
I put away mine a few months ago and was unaware that somehow a lot leaked out and formed a 3d shape, a thick disc.
On examination I was impressed with the material, resilient, but not a very high Q, and I was left thinking it would be good for casting.
I put away mine a few months ago and was unaware that somehow a lot leaked out and formed a 3d shape, a thick disc.
On examination I was impressed with the material, resilient, but not a very high Q, and I was left thinking it would be good for casting.
@ PeteMck,
Hi , I find this topic fantastic,
With your permission and mods ones, could we make this thread about receips to find DIY coatings according the driver materials and goals please ?
We had already some very usefull inputs from Pano and others but I'm sure many guys had kitchened some receips as well. A not easy one is about a non drying tacky & light material. the non drying tackyness for damping not only on the surface seems a challenge...
Hi , I find this topic fantastic,
With your permission and mods ones, could we make this thread about receips to find DIY coatings according the driver materials and goals please ?
We had already some very usefull inputs from Pano and others but I'm sure many guys had kitchened some receips as well. A not easy one is about a non drying tacky & light material. the non drying tackyness for damping not only on the surface seems a challenge...
I'll take the risk.
Having bought a very expensive second hand pair of speakers I was concerned about the rubber surrounds to the woofers, I've seen cracked ones over the many years.
After a lot of Googling I came across a letter written to Von Schwiekert on the subject of preservation, and he replied to the writer to use Caikleen rubber cleaner and preservative, saying that it would give another 50 years to the surrounds.
I forwarded this letter to the speaker maker, and they OKed it, but warned against getting it on the cones.
I've used it without problems, and, living on the coast with high UV and salt levels feel assured.
Having bought a very expensive second hand pair of speakers I was concerned about the rubber surrounds to the woofers, I've seen cracked ones over the many years.
After a lot of Googling I came across a letter written to Von Schwiekert on the subject of preservation, and he replied to the writer to use Caikleen rubber cleaner and preservative, saying that it would give another 50 years to the surrounds.
I forwarded this letter to the speaker maker, and they OKed it, but warned against getting it on the cones.
I've used it without problems, and, living on the coast with high UV and salt levels feel assured.
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