MTFCA Forum

What kind of wood, and what type of glue is used on laminating bows? I need to do 1 bow on a non Ford car.

Steve, several questions for you first. Do you have access to Oak that has not been kiln dried? Also, do you have access to a steam box??

Since we do coach work in my resto shop, we use Ash that has been air died to around 15%-17% for body wood with the exception if we are making sills or roof rails in closed vehicles. In your application, we generally prefer using White Oak or Chestnut Oak because we can bend it easier over Red Oak.

As far as adhesives (i.e.:glues) go, we tend to use an epoxy adhesive made by Total Boat however I am sure you can use Titebond III glue instead. The key to glue-ups is do not squeeze the clamps so much that it forces the glue out between the laminated layers. As I am sure you already know, you will probably need to build yourself and jig where you can slightly overbend it to compensate for any spring back once the adhesives have dried. Good luck, and make sure you have several extra pieces of stock to work with in case of splintering.

When duplicating a broken bow I found I needed;
A former around which the laminates can be clamped
Numerous G clamps
At least 8 thin strips of sawn timber of greater width than the finished bow.The thinner the strip the easier it is to bend.
Titebond 111 glue

I did not need a steamer, as the thin strips can be bent dry and cold.
I start with just two strips to glue together. They are allowed to set overnight. You may be able to add two more next day, but adding one at a time is easier.
When you have built up the bow to the correct thickness, you can then work it down to the correct width.

Laminated bows have less springback than steam bent bows, so you do not want to go overboard with bending them past square too far. If you do, pulling them apart to fit them may well induce a sag in the top. It is better to have a slight crown, so go easy with the bending them too far.

Hope this helps.
Allan from down under.

I am doing the upholstery and top on my 25 Touring restoration and found an alternative for top bow repairs in "One Who Collects" youtubes. He glues together 4-5 1x4 pine boards and cuts the bow corner wood sections on a band saw sized to fit into the bows. Those sections are covered up by bow cover material and the top, and it looks like they will be just as strong as a laminated bow corner. Take a look at the youtube. MIght be a good alternative for your top repairs.

Steve,

I used thin layers of oak or possibly ash. Maybe 8 or 10 layers, can't recall now. For glue, I used resorcinol marine glue. I made a form, with corner pieces and restraining blocks screwed down to a sheet of plywood. Laid down the first strip, brushed on glue, added the next strip, more glue, etc., etc. It was a huge mess. Use temporary clamps with the addition of each layer. Spring clamps should work well for this. Wear gloves. Use plastic, or some other barrier, to prevent the oozing glue from gluing your workpiece to the form itself. Have way too many clamps on hand, (and you'll find that you still may not have enough!). Clamp the layers together and clamp against the forms, especially at the corners. When I removed the clamps the next day, the bow had zero spring back and was rock solid. Sanding and dressing down the bow produced a really excellent piece. My dad shaped the ends for a nice tight fit in bow sockets. He was an artist with that kind of thing. Good luck!

Are all the thin strips being used alternating grain directions as is done in standatd plywood production? I can't read the answers in all the replies, and would assume it to be so, but think the answer is important to be included in this thread for posterity.

RVA23T wrote: ↑

Tue Aug 20, 2024 2:29 pm

Are all the thin strips being used alternating grain directions as is done in standatd plywood production? I can't read the answers in all the replies, and would assume it to be so, but think the answer is important to be included in this thread for posterity.

The grain all runs in the same direction, aligned with the length of the bow. Just as one piece of natural wood would do.

Ok I was thinking the added strength of cross grain would have been beneficial but it seems easier flexibility for forming/ bending is more important.
Thanks

As an aside to true lamination of hood bows, I was looking at making some curved sections for the body at the corners. The originals were cut from a wide board, and consequently as the timber aged and dried out, they were splitting across the grain. I found the solution in some modern foot wide laminated beam material. I scored an offcut for zilch and made my two curved pieces, filed them to fit and screwed one in place, and it promptly split! DUH. As all the grain in all the laminations were running in the same direction, my section of laminated beam was no better than what I was replacing!

I should have glued some sheets of plywood together.

Allan from down under.