What glue for dustcap?

[event horizon]

Hi everyone, i have a couple of pairs of 15" bass drivers that i'll eventually be incorporating into some sealed boxes. The thing is the standard dustdomes (or dustcaps if you like) have a rather large portion which is almost perfectly flat With some pressure, though with less than i'd need to move the cone the same amount it flexes quite a bit.

Well i managed to find some smart 8" dustcaps & my intension is to glue them over the top of the originals or even remove them. A little extra mass won't affect the drivers unduly, not with the cone thickness

I ust don't know what'd likely be the best glue to use as the cones are covered in some kind of coloured finish which appears quite glossy. I thought of contact adhesive but quite frankly i'm not sure how accurately i could place the cap centrally if i use it, i'd have ust the one shot

So obviously any suggestions would be appreciated - thank you!

A few pics so you can see what i'm dealing with.

[stoc005]

Try Duco cement or Ambroid. Both can be removed with acetone if you wish. Most hobby shops carry Ambroid.

[event horizon]

Cheers for the reply stoc005

I have a feeling that the solution has just occured to me I don't actually need to use "glue", i can do the job with something that'll definately bond the two bits together - RTV. No idea why it didn't occur to me before i posted.

Well it might help someone else. I'm not sure about the adhesives you mentioned simply because they may not be available in the UK, but thanks for suggesting stuff

[tinitus]

Originally Posted by event horizon

I thought of contact adhesive but quite frankly i'm not sure how accurately i could place the cap centrally if i use it, i'd have ust the one shot

Contact adhesive
Its not that I recommend it now, but regarding your concerns, it is possible to wet glue with contact adhesive
Takes a long time to dry, but gets quite strong and tough, and slightly flexible

[Don Hills]

Originally Posted by tinitus

Contact adhesive
Its not that I recommend it now, but regarding your concerns, it is possible to wet glue with contact adhesive
Takes a long time to dry, but gets quite strong and tough, and slightly flexible

I use contact adhesive, applied as a bead to the edge of the dust cap. It stays wet long enough to reposition if you get it wrong (though the glue may smear and leave a mess), and it dries quickly because the dust cap is porous, allowing the solvent to escape.

[al meta]

loctite 4105 (black tack) is used by many, there are a few other black loctite products that may also be suitable, but i have only used the above, just dont spray too much accelerator on it or it will bloom and look ugly.

useful guide here:

A Recone Guide - Speakerplans.com Forums - Page 1

[event horizon]

Excellent, thanks for all the replies people

I might try the contact adhesive wet as has been suggested, at least i'll be able to apply it easily enough. What i think i might do is accurately position the dustcap & then carefully mark around the edge with a pencil, then apply the adhesive to the cone, rather than the cap itself.

I think i'm likely to get it aligned better & with less mess

Cheers for the link al meta

[al meta]

i wouldn't glue before putting the dustcap in place, unless you intend to do a secondary bead afterwards, as you need the glue to fill the corner created between the two for a strong bond, and you don't want to smear glue over the cone whilst trying to alighn them, i can't see contact adhesive working very well tbh.

and i don't really understand why you want to glue new dust caps over the old..? it will lower the fs by increasing mms, but the motor strength becomes more of a factor for cone control. just get better suited drivers!?

[event horizon]

Hi al meta, as i mentioned (or at least i think i did ) the standard dustcap is mostly flat apart from a few raised sections. The consequence of this is that the thing flexes very easily, i'm not the kind of person who'd put up with the standard dustcap literally doing it's own thing while at least having control over the cone.

As the driver will be mounted in a 50L sealed box & the pk-pk xmax is 35mm there will be a lot of air compression in the enclosure. The voicecoil is vented through to the back of the magnet assembly so my guess is that the original dome will be flexing away willy nilly.

That's the last thing i want as you can possibly imagine. I can make the centre of the dustcap move 0.5cm in the centre whilst the cone actually moves less due to the rather stiff suspension

I'll take your recommendations into consideration, cheers for your input

[ashok]

I use a rubber based glue. Like the ones used to repair bycycle tires. These are available here in tubes also and there seems to be hundreds of brand names ! They can be removed easily after some initial soaking with a solvent , and there are many that will remove it. I use Amyl Acetate .
You just apply the glue on the dust cap. Align it into the proper position and leave it there for several hours. You can move it around for several minutes till the solvent starts evaporating. This takes time but give you enough time to adjust the position of the dust cap in case it's skewed.