>>>It will be fun to see how you make out with this.<<<
This guy has all the materials, glues and instructions you would need to do a project like this. When I started, I assumed it would be as easy as gluing two pieces of wood together. I ask this guy Joe a few questions by Email and realizing I didn't know what I was doing he responded by saying "Hope this helps in some way." Why would he put it like that? It was at this moment I realized I might be in way over my head. This website has many articles about veneering. I haven't read all of them but I read a lot. In addition to warping, there are bleed through issues, bonding issues, temperature limits, water content of the wood recommendations, advice on humidity, curing times etc. For a while, I thought I'd go through all this effort and cost and end up buying a plywood dashboard from Langs when it was all over because there a 50 different ways I could fail. Today, I'm feeling a little more confident.
My first attempt at gluing the cherry boards to the substrate was a failure. I was using a 3/4" plywood with weight on it but I didn't have enough weight or glue apparently. See how the boards started to curl? So I aborted the project and read more about it.
One of the articles I read (after this failure) recommended 1300 to 1700 lbs. per square foot or 9 to 12 lbs. per square inch. So I set about to build a press.
The base of this press is a saw bench. There are several videos on YouTube of building these. No nails or screws - it's all glued together dovetail joints and walnut pegs.
This bench turned out as solid as an anvil although my dovetails look like crap. Good enough for shop furniture. Counter intuitive, but it's easier to get a nice looking dovetail with hardwood. Soft woods allow the fibers to tear and be distorted. Hardwoods give me a clean cut line. But even if this joint isn't done well, it's just crazy strong.
There's a link on Joe's site to American Woodworker with plans for the press:
So I put down a layer of glue on the firewall core to prevent the substrate from sucking all the water out of the solution before the chemical reaction takes place which gave the dashboard this caramel color. I wet the other side of the 1/16th inch cherry boards before applying the glue trying to achieve a 8% to 12% water content of the wood. If you're interested, the glue instructions are here:
So the first side of the spacer cherry turned out flat and OK. I'm starting to think I might pull this off.
(Message edited by jesselashcraft on February 25, 2018)
Well I gotta say, those are pretty darn fancy saw horses you made! I hope you have glued the other side on by now, and how did it turn out? I was thinking it would be good to glue up the other side before any bowing of the core could happen. I know it is very important to keep laminated panels balanced, so the same material and amount of finish on each side.
I suppose you want it that way, but you have the grain going the wrong direction for the core, and the veneer. Great looking little bench you made. Those dovetails are difficult to do.
>>>I hope you have glued the other side on by now, and how did it turn out?<<<
I hear ya, Ray. That was a concern of mine. But the Ultra Cat veneer glue I used is touted to harden so rigid as to become a structural member in addition to holding the wood together. Great product for a beginner like me. Since it cured five hours in the press, that sucker was flat. A couple day passed between sides and there was no warping that I could see. Since I wasn't worried about bleed through for this layer, I spread it on both the cherry and the core like a typical glue up job. So far, so good.
(Message edited by jesselashcraft on March 01, 2018)
Hi Larry - these cherry 1/16" thick boards aren't the finish veneer. I needed to make up 1/8" so these went on both sides. I put them vertically on the horizontal core boards to enhance strength. I bought another glue for the finish paper layer. It's premixed and is thicker to prevent bleed through. Only the substrate gets the glue this time. I'll put the top layer on with the horizontal grain.
That saw bench will come in handy as a place for car club members to sit and school me on Model T behavior.
Beautiful workmanship Jesse! I especially applaud your use of a brace & bit. That's dedication!
Jesse, at this point you should double check that the final thickness will be such that your brass molding will fit ok. You can still sand some off the first cherry veneers if you have to.
My first attempt at applying the paper veneer to the dashboard was a failure. According to the guy I bought the glue from, I apparently need 65 degrees or better for the special glue to set up properly. My refrigerator termometer indicated it was 68 but the guy I bought the glue from said it must have been below 65 because the glue was still tacking after an hour and started to bubble up immediately after the press was removed. Had to throw away a $25 piece of veneer and scrape that tacky mess off and resand the cherry substrate smooth with 60 grit. That hurt, so
1) I invested in a nice outdoor patio termometer for the shop and
2) here's a picture of a practice clamp up I'm going to use next time. 20 clamps, 4 through the center of the platen boards to match the transmission cutout, should get me well above the 9 pounds per square inch I need to make the glue set up properly. As soon as the weather gets to where my kerosene heater can maintain 70 degrees or better in the shop, I'll try it again.
Interested to see how your last gluing went!
Bump above the spam.
>>>Interested to see how your last gluing went!<<<
The time it took to build the press was worth it. It appears this project is working out well for now. I glued one side and put it in the press for an hour. I had the press off for about 45 minutes while I drilled the holes through the new veneer and glued up the other side, then back in the press for another hour. Warping was a big concern of mine. I got both sides glued up within a couple hours. There are two diagonal corners of the firewall that are out of flat by 1/16". That's it! (It's been about 48 hours and I think I'm out of the woods). I couldn't be happier about that.
Here it is resting for 24 hours in it's custom "dual side concurrent glue curing stand."
(Message edited by jesselashcraft on April 15, 2018)
Very nice work. Thanks for taking the time and pictures to share with us.
Nice! It looks like the top corners are slightly radiused. is that the veneer overhanging?
That looks more beautiful every time you work with it. Then again I think the core itself is pretty cool looking!
Thank you for bringing us along with you! Wood fire walls are just so dang gorgeous!
I WAS thinking how does your thread apply to the T's here even tho I'm enjoying it immensely.
It hit me just now. My 18 has had a repro next-gen-later firewall in it for the last 30 years and it needs to be replaced.
It's similar to yours but the core was built up of larger materials and veneered. Then painted black I 'spose.
You provide thoughts for a fella that won't see the forest for those darned trees here. Did that make sense?
I have some of the original firewall yet and could build a new one to suit. Hehehe! Do I stain it like Martin Vowell's? Yup.
Sorry for the babbling.
A big thank you Jesse!
>>>It looks like the top corners are slightly radiused.<<<
Hi Ray - I got one of those edging router bits with a wheel on it and the wheel rode around the core edge. So it's slighly rounded at the top corners. You were right about the new veneer being a little too thick for the brass. I was actually thinking of putting a filler piece of wood in the brass for the molding to ride on then screwing that to the firewall. In a few years, I could remove the brass and see if shrinking occurred making the wood filler unnecessary. I'm new to veneer and at this point, I'm a little hesitant to go after this thing with a block plane.
>>>Then again I think the core itself is pretty cool looking!<<<
Yeah, like I said in an earlier post, if the dashboard was plywood, I would have hung it on the wall of the shop, tacked some pictures to it and order a new one from the catalog. That was back in the day when I thought veneering couldn't be much more difficult that gluing wood together. I was wrong. But I'm glad I was able to save the core and I learned a thing or two about veneering in the school of no mercy.
If there's a core you want to work with and the veneer is starting to peel anyway, invest a good Japanese slick. It's a chisel with a 2 1/8" blade. It's two feet long and if the piece is clamped down, you can really lean into it. I had to use my 1.5" framing chisel with a mallet on some stubborn parts but mostly, the veneer came off with the slick.
(Message edited by jesselashcraft on April 18, 2018)
The wood firewalls are certainly nice looking and I had to rebuild my 15 as well. I had all the original pieces to copy and there was a few small pieces of the original cherry veneer skin. The cherry veneer on mine was one solid piece but the grain was vertical. In it's earlier life a PO had reinforced the wood assembly with two pieces of flat iron attached horizontal across the wood. The original pieces are tongue and groove and I don't know if they are glued or not, there was no evidence of any glue on the one I disassembled. As they are bolted solid to the frame and will flex and therefore are subject to cracking. On my original assembly the tongue and groove boards were all in tact but the veneer was over 90% missing. As the assembly was allowed to flex the veneer would not and progressively cracked away leaving a bare tongue and groove assembly. I think it would be a good idea to mount the wall so that it can flex with rubber grommets.