Need help with veneer...

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mas

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Re: Need help with veneer...
« Reply #20 on: 3 Jun 2007, 12:26 pm »
Bill A, if I move the speaker around, the dark piece lightens to the same color as the neighboring pieces. The first speaker I finished does not exhibit this problem, remaining uniform in color from various angles. Actually, this is more an item of  curiosity than a problem. Wood varies naturally, and that is part of its beauty. So, I'm  still not sure what happened, but the softener was the only thing materially  different between how I did the two speakers.

Rod, I am a woodworking novice. I got a router in December, and bought my table saw in February. This was my first project.  My first set of cabinets didn't turn out well, so I had to spend another $30 for more MDF. The time wasn't wasted because I learned how to do it better the next time. I've had a lot of fun, mistakes and all. I might not have started except for the great help available on this board.

World Leader Pretend

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Re: Need help with veneer...
« Reply #21 on: 3 Jun 2007, 07:01 pm »
I have a question,

can you use some cheap paper-backed veneer (like oak or maple or something inexpensive) and paint the veneer with a gun to make a piano-gloss black look?  This would help the speakers to look professional and hide any woodworking blemishes. 

Would this work?

Danny Richie

Re: Need help with veneer...
« Reply #22 on: 3 Jun 2007, 07:24 pm »
Oak is a good wood to paint because the heavy grain will still show through the paint.

We used to offer some speakers in a gloss Black painted Oak. They looked great.


slksc

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Re: Need help with veneer...
« Reply #23 on: 4 Jun 2007, 02:14 pm »
Before anyone tells me to used paper backed, remember I got this veneer for $25!

A great bargain, no doubt about it.  But if you add up all the hours of grief that veneer has caused you, and if your time were worth $0.25 an hour, you could have bought gold-plated veneer and still have some funds left over!  :lol:

Just kidding.  You did a great job on those AV-3's, and in the end that's all that matters.

Daygloworange

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Re: Need help with veneer...
« Reply #24 on: 5 Jun 2007, 12:28 am »
I have a question,

can you use some cheap paper-backed veneer (like oak or maple or something inexpensive) and paint the veneer with a gun to make a piano-gloss black look?  This would help the speakers to look professional and hide any woodworking blemishes. 

Would this work?

It could. However, there could be some movement in the veneer, and either the grain, or seams, or knots could print through in the finish. A good clear maple veneer might work underneath paint. Black is the most revealing of flaws, piano black much more so than a satin.

Cheers
« Last Edit: 5 Jun 2007, 05:20 am by Daygloworange »

Daygloworange

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Re: Need help with veneer...
« Reply #25 on: 5 Jun 2007, 02:34 am »
A new problem surfaced however. The bookmatched pieces did not stain uniformly as they  did on the first speaker. The pieces of veneer are  alternately light and dark (see the second picture below).

This is not a problem you caused, it is caused by the the lay of the wood grain.  When the book match was made, the veneer pieces did not just slide over to make the piece wider, but rather they opened like a book.  In doing so, the grain direction flopped 180 degrees.

If you change the direction of the light or flip the cab upside down, you should the light and dark area reverse.

Very nice job, BTW.

Bill

The problem in color could be due to the residue of glycerin in the veneer softener. It's been known to take a long time to evaporate, and some feel it actually causes problems with some types of finish.

However, it might not necessarily be due to the softener. What Bill says regarding veneers is true. Here are some pics of some tiger sycamore:

These are sequenced as they were sliced off the log, one slipped over the other.



This is showing them bookmatched. Notice the color in between the two lines.



The same bookmatch, photographed from the same angle, only the veneer has been spun around 180 deg. Notice the color in between the two lines.




Now the bottom photo spun 180 deg. and put underneath the first one.



Sometimes the alternating dark/light in the bookmatch shows in the unfinished veneer, yet when stained, looks even. Sometimes it's vice versa.




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Another problem is that I can still see residue of the veneer tape (not picked up by the photos). I used TSP and it looked clean before stain, but next time I will use mineral spirits to clean up. 

Mineral spirits will not work. The adhesive is water based,  very sticky, and stubborn. You need to scrape off as much as you can while it's slightly dampened with water, then if there is any residue still left, dilute that with water. If you are in doubt that you've removed it all, wipe the area with lacquer thinner, or mineral spirits (this will expose it, not remove it) . If there's any left, you'll notice it then. You'll need to keep cleaning it with water to get it off.

A similar trick to find these little imperfections is to use some stain that is very diluted, and wipe the veneer. A stain high in pigment vs dye works best here. The pigments will highlight problem areas. Of course if you are not going to apply a stain, and just leaving the wood it's natural color, this method is not a good idea.

On the topic of adhesives. I just used some of the Titebond type III adhesive on a pair of OB 7's that we are currently building for a customer. I had some leftover dry on a piece of melamine, and I tried to scrape it off. It was stuck to the melamine like a cat on a screen door. :o I was hacking at it with a planer blade, and it was really giving me a hard time. Regular PVA glue, by contrast, just peels off.



It appears this stuff (and the type II adhesives) might indeed be a better suited as an adhesive for veneers.  :P

Cheers



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« Last Edit: 6 Jun 2007, 02:56 am by Daygloworange »

mas

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Re: Need help with veneer...
« Reply #26 on: 6 Jun 2007, 01:26 am »
Thanks for the great post, Daygloworange. 

I am still blaming the veneer softener. The other speaker does not exhibit this problem, and I used veneer from the same sequenced set on that one. The only difference was one used softener and the other didn't. 

I like your suggestion of using a dilute stain to find discoloration issues on the veneer.  Great idea!

I chose Titebond I over Titebond III because of the difference in temperature required to iron on the veneer. According to what I have read, the Titebond I requires a much lower temperature.

Actually, now that I think about it, I ironed the hell out of the first speaker compared to the second. I had to sand quite a bit to remove burn marks from the iron on the first speaker. I used cotton towels with  steam on the second speaker and produced no scorched marks whatsoever. So, the differences between the two finishes could also have been cause by heat or sanding differences.     

I recently learned that sapele is a threatened species, so I have chosen a flat cut birdseye maple for my OB-5's. Is this veneer susceptible to this issue? Any issues with maple I should be aware of?   Is maple suscetible to cracking? Can I skip the use of veneer softener?



 

Daygloworange

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Re: Need help with veneer...
« Reply #27 on: 6 Jun 2007, 02:10 am »
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I am still blaming the veneer softener. The other speaker does not exhibit this problem, and I used veneer from the same sequenced set on that one. The only difference was one used softener and the other didn't

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Actually, now that I think about it, I ironed the hell out of the first speaker compared to the second. I had to sand quite a bit to remove burn marks from the iron on the first speaker. I used cotton towels with  steam on the second speaker and produced no scorched marks whatsoever. So, the differences between the two finishes could also have been cause by heat or sanding differences

The veneer softener might well have a lot to do with it. The bottom line is, that, your speakers were two different projects. Two different approaches, and ultimately two different results. Sometimes it's not that easy to isolate where the problem actually is.

As a note, there are certain things we never do separately. For example, on a pair of speakers, we do everything to both pairs, at the same time. We don't veneer, sand, stain, or finish one speaker on one day, then do the other. We do them together, at the same time, at every step. Particularly with the final stages.

Sanding for example. We use D/A sanders for the bulk of sanding, but finish by hand with sanding blocks. We will do the speakers together. Your hand pressure on the sanding block will be different everytime you sand. So you do them close together. Not one speaker in the morning, then one late in the afternoon, or the next day. We can actually adjust the darkness of color (when staining a speaker) by sanding. Some people might think that's overkill, but it's not. When we run a job with a lot of panels, or doors, we will sequence the job, so there will be no interuptions in the task, be it sanding, staining, or finishing. No exceptions. Without this, consistency, is hit and miss, even for really experienced people.

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I like your suggestion of using a dilute stain to find discoloration issues on the veneer.  Great idea!

Yeah, works great!  :green:  More importantly, it'll highlight any sanding scratches or swirls that have been missed, that'll show up tremendously with fully concentrated stain.

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I chose Titebond I over Titebond III because of the difference in temperature required to iron on the veneer. According to what I have read, the Titebond I requires a much lower temperature.

I don't have a lot of experience with the Titebond adhesives, so I can't comment a whole lot. And we don't use any heat set methods. We use primarily PVA adhesives, and I really can't remember any failures. With paperback veneer, we use contact cement, and have never had any failures or issues of any kind.

Quote
I recently learned that sapele is a threatened species, so I have chosen a flat cut birdseye maple for my OB-5's. Is this veneer susceptible to this issue? Any issues with maple I should be aware of?   Is maple susceptible to cracking? Can I skip the use of veneer softener?

Figured woods are usually more brittle and difficult to work with. In solid form as opposed to veneer, they can be tremendously difficult to work, and machine, without tearout problems and so forth. But the birdseye veneer shouldn't be too bad. If it's paperbacked, it's been tenderized, so much easier to work with and is also less prone to splitting due to both the paperbacking, and that the tension in the fibres is broken during the tenderizing process.

In regards to the veneer softener, from what I understand, the water does the majority of work, but very temporarily. The glycerin is there to keep the veneer in a moist, plyable state, as water evaporates very quickly, and the veneer can (and usually will) do unpredictable things as it's going back to a dry state. It can buckle, and crack very easily. But apparently the glycerin can affect the colour, and adhesion of finishes.

We virtually never use veneer softener, but I have used it in the past, with caution, but prefer not to, just because there is not a lot of concensus on the process and answers to troubleshooting in the event that problems arise. We've been able to for the most part manage without it, but with standard cabinetry, we don't usually do things that are sometimes called for with speaker building.

Cheers





« Last Edit: 6 Jun 2007, 02:30 am by Daygloworange »