Veneer Issues - Premade box - African Mahogany

[andrew whicker]

Hi,

As the title suggests, I'm having problems w/ chipping when I am removing the extra veneer that is hanging over the edges. I've been overhanging by a small amount and then using a metal file to remove the rest (instead of a rasp as my book suggests). This veneer is NOT paper backed. The way this particular veneer acts, it is very brittle. I was afraid in advance that this might happen.

I was wondering how to get away from this issue? Cut the overhang very closely to the box and then lightly sand the rest of the overhang off? I have another practice box made up. I'll try that method next. I'm just using TBII for glue since this box isn't going to become anything. My end goal is to veneer pre-made speaker boxes. Obviously, I have a ways to go first. I thought maybe it was a glue issue, but I think by my last panel I was very honed in on getting all the corners glued.

I'm up for any advice. I've also thought about trying to repair these problems. I imagine using veneers regularly requires good repair knowledge.

I will have to practice with contact glue and UF glue in the future. These are the glues I'd prefer after doing some reading, etc.

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Cheers,

[Kevin Jenness]

First, use a sharp, fresh flush trim bit and a slow feed rate. Climb cut at the corner. If the fault is that the veneer is brittle then you can use an oversize bearing and sand to finish. Direct the sanding force from the veneer face toward the substrate. Try a different veneer to see if that is the issue.

How are you clamping the veneer? If using clamps and cauls that can require considerable care on an assembled box to get pressure where needed. If you are planning on doing much of this a vacuum setup with a bladder inside the box may be the way to go. I think you can find info on this process at the vacupress site. Stay away from contact for raw veneer.

[andrew whicker]

Yeah, I was thinking of the oversized bearing idea. Sounds mostly fail free to me. Will do on the sanding.

This box is like 5" x 5", so I just a spare oversized (6" x 6") BB plywood on top of the applied veneer and clamp it with like 6 to 8 clamps. The veneer seems very flat.

Yeah, the actual speaker box is going to be a new science project. One step at a time. However, I am reading that many professionals use vacuum bags for pre-made speaker boxes. I like the bladder idea. There was conflicting info on whether the speaker cabinet collapse potential is a worry or not. Best to be safe.

Also, I was surprised to learn that many people who have experience with this type of veneering only vacuum clamp the veneer for ~30 minutes. I was expecting 2 hours or so.

[johnny means]

I wouldn't touch veneer that thin with a router. Several passes with a sharp knife will do the job. I clean up with sharp chisel or plane blade. Hold it flat on the surface with tde edge skewing inwards. Good adhesion is everything. You're right about repairs, dealing with imperfection can be the biggest part of the job. With thin veneer like that, I cut a small piece or, better yet, find the missing bit, and glue it in place using tape to clamp it down. Alternately, the patch can be fast set using an iron.

[Robert Engel]

I agree do not try to flush trim it. I've tried climb cuts, offsetting with a few strips of tape, etc. but brittle veneer its just too risky.

Back it up and use a plane blade or flat single bevel marking knife like a Hock knife, but any razor sharp knife will work.

You can also offset with a piece of thin shim stock and finish by sanding with hard block.

[Phil Mueller]

I use a fresh Xacto blade or a hobby scalpel (easily found on the internet) and make numerous light passes, then sand flush. If I’m cutting through a lot of glue squeeze out, I’ll change the blade often. Many will say the best way is to glue the veneer to an oversized substrate, then cut the substrate to size. I don’t do it this way, but might be something you want to try.

Veneer patching, especially a small chip out is challenging. I keep all the veneer cut offs and try to match grain and color as best as possible. Or as Johnny said, find the piece that broke out and use it. It’s also difficult to fit an odd shaped space, so if needed, I’ll cut out a triangle or some other shape and fit the patch.

You can watch a lot of veneer repair on YouTube..check out Thomas Johnson furniture restoration. Many of his videos cover veneer repair (not all, but search through his vids and you’ll certainly find one).

If it’s a really small repair, you can sometimes get away with just “crushing” a very small bit of veneer into the flaw with a little glue.

The other thing I spent a little on is shellac melt sticks. You can get them in different colors, but I tend to just go with clear. Often you can fill small gaps/holes with a little hot melt shellac and plane/scrape/sand smooth. If the substrate is a close color match, no one will ever know.

And one last tip...as you know, commercial veneer is thin. It can actually take a bit of sanding before going through, but to be safe, I leave all sanding to the end and only by hand. In other words, if I make a small repair, I don’t sand it flush at first. I wait until I’m going to final sand the whole piece. Less sanding means less chance to go through. And unless something is really rough, I usually don’t use anything coarser than 220. And, keep in mind that if you’re using a film building finish, it’s that finish that will be sanded smooth. So in other words, it’s not critical to get the veneer perfectly smooth. It just might take a few extra coats of finish to fill any minor grain variations.

You’ll find after a few projects that it’s far less intimidating than it seems at first. Have fun.

[Richard Coers]

You can cut it from the back with a special veneer saw. The teeth are filed like knives and is smooth on one side to rub right against the base edge.

[Kevin Jenness]

There was conflicting info on whether the speaker cabinet collapse potential is a worry or not. Best to be safe.

If you put a speaker box in a vacuum bag it will probably collapse and certainly distort unless it is supported inside with bracing or a bladder connected to the outside atmosphere.

Also, I was surprised to learn that many people who have experience with this type of veneering only vacuum clamp the veneer for ~30 minutes. I was expecting 2 hours or so.

Depends on the adhesive and temperature. I allow at least an hour for pva glues at 65 F.

[Curt Putnam]

I just skimmed the responses so this may be a repeat.

I would consider softening the veneer with mineral spirits. That plus an uber sharp knife should do the trick. For the knife, an Exacto blade might work - especially of carefully stropped. Otherwise, a Japanese marking knife or something similar would be my wweap of choice.

[andrew whicker]

The cutting super close followed by the sanding block worked well so far.

[andrew whicker]

Another question:

I see a lot of speaker boxes where there isn't any indication of veneer end grain and I know these veneer specialists are veneering pre-made speaker boxes. I'm assuming they are mitering the sheets.

When you do this, I'm assuming it needs to be done after the sheet is glued onto the box. Is this the case? I'm at a loss how one would do this. Tablesaw? Router bit somehow?

Example:
https://www.lumberjocks.com/projects/45776

[andrew whicker]

Maybe a bit like this and a fence?

https://www.amazon.com/HSS-45-Degree-Dovetail-Cutter/dp/B0067BTX7M

Seems like tearout would be a major issue..

[Mike Henderson]

It looks to me as if the veneer is not glued down sufficiently. The glue joint between the veneer and the substrate should be stronger than the wood. When I saw, or otherwise process, a glued panel, the veneer essentially acts like it's part of the underlying wood.

For things like what you're doing, I use standard white glue. Only put glue on the substrate. How much glue to put is a learning experience. Too little and you'll get poor adhesion. Too much and you'll get glue bubbles under the veneer. I use a roller to apply the glue.

Make sure the substrate is clean before applying the glue. If you have any questions, sand the substrate to expose clean wood.

DO NOT use contact cement on raw wood veneer. Contact cement can be used for backed veneer.

UF glues will work fine but the set time is long. Leave the work in clamps or a vacuum bag overnight or most of the day.

If you get a bubble from poor adhesion, slit the bubble along the grain and work Gorilla Glue under the veneer. Press the bubble down with some plastic between the veneer and a caul.

Good luck.

Mike

[Phil Mueller]

When using thin, commercial veneer, end grain isn’t really an issue. Glue it down, cut off the overhang with a sharp knife, lightly sand. Here is a tissue holder I slapped together. As you can see, end grain isn’t visible.

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[Jim Matthews]

The local artisans using veneer on a regular basis favor Cascamite. Veneer *can* be applied with Titebond and a spare electric iron.

https://protradecraft.com/video/forgiving-approach-veneering-woodwork-titebond-and-iron

If this is your first attempt, it's pretty good.

You have already discovered the necessity of doing this sort of thing with sharp, slower hand tools due to the fragile nature of veneer at the ends.

As Phil mentions above, using a *fresh* utility knife cutting from the adjacent edge will generally yield the best results for the occasional user.

If you have lots of these to make, a spiral down cutting router blade with a bottom bearing is designed to shear the edge with reduced chip out.

[andrew whicker]

Thanks for all the tips. My last box (3rd attempt total) turned out much better. For this box, I bought paper backed walnut. It was much less sensitive to breaking. I showed it to the speaker company and they told me I was definitely close to the quality needed.

This made me think that for now I should stick to woods that aren't brittle, maybe stick to paper backed specifically for now or thicker veneer. I will also need to learn how to sew pcs together as customers like bookmatched. I'll turn down work requests that are outside of my range or require me to have more knowledge. I'll get there eventually. Is oak also brittle in veneer?

I also need to be more careful with material waste in order to give the best 'waterfall' look I can. I got one edge to be nearly perfect, but I was clearly off by about 1/2" on the other. For practice I was less interested in this aspect. The next box I do, I will plan it out like a speaker box. I.e. only the back of the speaker box doesn't have a waterfall look on any edge. Where as for practice, I was just keeping it simple and using one long strip of veneer resulting in waterfalls from side 1 -> top -> side 2. Sides 3 and 4 were independent.

Blue tape has helped a lot. It's still hard to know that your veneer sheet is square to the face of the block you are veneering. Clamping tends to move the sheet around a bit, so I find myself constantly adjusting the sheet. Maybe I could wait for the glue to get a bit tacky?

I'm also going to try UF glue soon. Currently using TBII

[Mike Henderson]

To get a good bookmatch, you need to align the two pieces of veneer first, and then trim or flatten them together. If you can find an experienced veneer worker in your area you could probably get some valuable tips.

I don't know if this will help, but I have a tutorial on doing a simple veneer project here (https://mikes-woodwork.com/RectangularTray.htm). I'm sure you can find others on the web.

Mike

[Kevin Jenness]

You have probably already realized that paperback veneer is very thin- typically .010" pre-sanded veneer on a .010" paper backer, so it doesn't allow for much further sanding. Raw veneer is typically 020"-.025" and thus allows for (but needs) more sanding. The main advantage of paperback is saving labor in matching and seaming. The downside is you lose control over the layout, unless you can specify to your supplier exactly what you want in terms of leaf width, book vs. slipmatching, etc. If you want to do your own bookmatching raw veneer is a better choice.

If you do settle on paperback you should look at FSV glue which is made specifically for that use- it is a fast tack pva that can be laid with a pinch roller or hand pressure somewhat like contact cement https://veneersystems.com/product/fsv-flexible-sheet-veneer-1-gallon/. You can use contact on paperback, but I avoid it for any veneer work. Either one may give you more control over lining up your veneered corners. Hammered hot hide glue with raw veneer is another option. Boxes with continuous grain corners (waterfall) are more easily done by veneering a long panel and then miterfolding the corners, but that is not what you are faced with.

To your original problem of crossgrain trimming edge tearout, you might consider this https://veneersystems.com/product/ulmia-740-edge-trimmer/. I have always had acceptable results with careful use of a laminate trimmer, but numerous comments on this thread led me to purchase this tool. I think that with a well-maintained blade it will be a reliable and efficient tool.

[Mike Henderson]

Paper back veneer is generally not recommended for furniture. Where it is used (millwork) people usually use contact cement, treating it like Formica. Like Kevin said, the wood is very thin and, depending on how you build your project, the paper can show.

I would recommend using regular, solid wood, veneer and gluing it down well. Well glued veneer will not separate at the glue line. There are a lot of good glues, but I often use plain white glue. UF glues are also good.

Mike

[andrew whicker]

thanks.

You're right. I better go w/ raw to reduce the impact of edges as much as possible. I'm also going to ask a local woodshop that has more equipment than I do if they can resaw some stuff for me.