vacuum bag

[richluvsound]

Hi, Guy's

I'm working on some cabinets with curves . I will be veneering with santos rosewood. Has anyone built a vacuum bag for such a task ?

Rich

[macaroonie]

Are you not using contact adhesive evo 528 ?

[Mr. Widget]

I use a vacuum bag... it can be tricky with large curved panels. You need to have incredibly robust patterns when making free standing panels like the front of a Paragon.

There is quite a bit of info on the web about how to set up a bag system and how to use them... do some google searches.

I also use contact cements... usually as a last resort or if the project isn't terribly important. I have found one way to make contact cement work well. I bond my veneer to some thin bending poplar in my bag press and then contact cement the bendy panel to the speaker... it works quite well and the whole panel will not lift like a bit of veneer can as the contact adhesive ages.


Widget

[richluvsound]

Hi Mac,

I wont use contact , Oil with act as a solvent and draw the adhesive to the surface on the verneer.

The sheets of veneer are too big , even using wax paper it's risky.

The surface is too uneven once glue is applied.

Rich

[richluvsound]

Gents,

for the substrate I'm using the same method as Majico. Horizontal segments glued and then threaded rod running vertical that act as a clamp and a register during assembly. Some of the techniques I have'nt tried before so your experience and comments will be most welcome.

Widjet, did you build your own bag ?

Rich

[macaroonie]

Pearl glue ???? I have tried it but did not really have a great success. I think I was missing a trick somewhere but it is the old fashioned way. Audiobeer could probably pitch in with something useful.
PS you can thin Evo to get a less lumpy spread and use a smeared coat as a primer. I built a kitchen island for a pal at least ten years ago with an oval base. I overlayed 4mm birch ply as an outer skin. The sheets were such that I needed 2 parts and no matter what the join was on quite a sharp curve.
Primed both sheets and then applied adhesive thinned with a fine notced spreader. Its still there to this day with no lifting. I do take your point if you are going to oil the veneer.
The new avatar signifies the onset of building.
What are you up to with those 4333s

[richluvsound]

they are staying original components , recone and new dia's. C C xovers and a change of colour ie, maple veneer and powder blue baffles. No more dark veneer, It will look like an undertakers or a bloody court room in here.


The curves are for commisions I have for other members. Current components. I fancy building some for me too !
:applaud:

[4313B]

The curves are for commisions I have for other members. Current components. I fancy building some for me too !
:applaud:I was originally going to build six Project May-type 1500AL enclosures, four for Don and two for me. I went so far as to route out the additional braces but then decided that it would be more fun to go retro, back to the 4320/4331/4333/4338-type boxes with the blue baffles. After all, the 4331 started the whole JBL 15-inch 2-way for me personally. My new 4338 grilles showed up last night. I already have the 1500AL's and the H4338's. You're using the ME150HS's and H4338's right?

[richluvsound]

Giskard,
from what Iv'e heard , the 4338 is the better horn . I'm inclined to trust the reports. The Fact that you are using it confirms it . The bottom end is still un-decided. I may have to wait till I move back to Canada or go the Japan route.
I know the horns are rare as hen's teeth . I also realise I'll have to respectfully nurture some relationships to realise this ambition.
I love my 4345's and the 4333's, but I have read a bit about the 2 way and my 4435's are a great champion of the cause. I guess Iv'e got the bug although all I can offer are my wood skills. Maybe in 10 years I'll know enough to really get into it . However, the schematic's you posted for L 300 xover look like a good place to start to cut my teeth.

The components you cited are indeed for One pair.

Rich

[Guido]

You're using the ME150HS's and H4338's right?

ME150H, yes. H4338, hopefully ;)

[Mr. Widget]

...for the substrate I'm using the same method as Majico. Horizontal segments glued and then threaded rod running vertical that act as a clamp and a register during assembly.I assume you mean Magico's Mini? They initially had lots of problems with delamination but eventually found a vendor who could pull it off... TAD has had the same problem with their original Model One. Magico has limited this technique to their quite small Mini, resorting to other manufacturing techniques for their larger speakers and TAD has discontinued this type of cabinet all together.



Widjet, did you build your own bag ? No, I bought mine about fifteen years ago... I don't use it that often and my original bag still works fine, but with a few patched pin holes.


Widget

[richluvsound]

Widget,

I was thinking - 1" moisture resistent mdf for the segments, veneered 1/4 ply exterior wrap and grp internal. I think the bag is a no -go for this project. the veneer is £ 190 a sheet. If it was my cab I'd have a go . I want my A game for this project.

your watchful eye is greatly appreciated,

Rich

[macaroonie]

Rich if that magico is what you had in mind as a route. Its insane from the point of view of machining time and the waste of material. I refer you to our conversation outside the pub. M

[LE15-Thumper]

Ok, I have never built fancy cabinets. What is the vacuum bag trick and how is it applied ? What is it's purpose ?

[John]

Hi Keith Google vacuum veneering and you should find some info explaining it.

It is for veneering.

[richluvsound]

Rich if that magico is what you had in mind as a route. Its insane from the point of view of machining time and the waste of material. I refer you to our conversation outside the pub. M

Yeah, not really. I'm not cutting the whole segment, only pieces to assemble individual panels. Besides, Widget has raised a valid point on the potential of de-lamination.
Mdf. may give way to chipboard . Chipboard is considerably more porous allowing for better keying for the resin.

I need to spend some time with vector works PDQ.

Rich