laminated stem

gaff · Post by **gaff** » Mon Jun 13, 2011 4:07 pm

I am laminating a new stem for my cedar strip runabout. I have read that you should use odd number laminates so you don't have a glue joint in the center.

The old outside stem was 7/8" thick so I was going to do a 1/4 + 3/8+1/4 layup after steam bending the strips. I had the 3/8 on hand making it easier to use in this application.

Is three layers adequate for the stem?

I was planning to use thickened epoxy but I have read that epoxy and white oak do not go well together. I was told to consider 5200 or PL Premium.

Any thoughts on this?

Thanks

Steve

LancerBoy · Post by **LancerBoy** » Tue Jun 14, 2011 4:07 am

I don't think odd or even makes any difference. Different thickness of individual laminations is questionable. Probably not all that big of a deal on something like this application. You, of course, will have screws thru the laminated stem attaching it to the boat.

Epoxy and white oak do not like one another. Resorcinol is the adhesive to use. Not sure 3M5200 or PL Premium are OK. Check past discussion forum posts about this at www.woodenboat.com

Below is a picture of a couple of glued laminated stems:

Andreas

gaff · Post by **gaff** » Tue Jun 14, 2011 8:15 am

Andreas

Thanks for the reply. I am going to look into Resorcinol.
Great photo!

Thanks again

Steve

LancerBoy · Post by **LancerBoy** » Tue Jun 14, 2011 3:42 pm

By the way, that is the Thompson Boat factory at Peshtigo, WI in the background. The glued laminated stems were made next door at Unit Structures, Inc. (Sentinel Structures, Inc. since 1973).

Andreas

Big Ray · Post by **Big Ray** » Wed Jun 15, 2011 5:42 am

Andreas,
What do you think of "Gorilla Glue" in a laminating application like this? I have found that in other applications it's a little ornary, but strong as heck.
Just wanted to learn from your experience.

Thanks- Ray

LancerBoy · Post by **LancerBoy** » Wed Jun 15, 2011 6:32 am

I really do not know much about Gorilla Glue. I have used it a few times for non-structural applications. It fizzes a bunch!

Andreas

Michael J. Seiber · Post by **Michael J. Seiber** » Thu Jun 16, 2011 10:59 am

First let me say, sorry I've been gone so long. That said I made a white oak laminate stem and keel for my Cruisers 202 four years ago. Worked perfect.
I did alot of experimenting before I decided what glue to use. I glued pieces of white oak with several types of glue and put them through a rigorous torture test. Gorilla glue won the contest hands down.
Keep in mind there are two types of Gorilla glue make sure you use the water proof type. Oh and also make sure you use lattex gloves. and don't get it on your pants or they will be glued to your leg.

If you go back a couple of pages you will find the topic with pictures how I did it. (Cruisers 202 restoration). It may helpful for you if you took a look at it. I don't think it matters if the number is even or odd

Michael J. Seiber · Post by **Michael J. Seiber** » Fri Jun 17, 2011 8:13 am

I went back and looked at the topic. I really didn't expain it all that well. I used green white oak and attached them to the stem of the boat putting spacers in between the laminates so air could go around them and left them dry that way. it took a couple of weeks and I used a fan blowwing on the front of the boat.

After they dried I took them off. They sprung back a little bit. I then made a jig on a flat table the same bend as the stem, glued and clamped it all together. Worked great.

t3 · Post by t3 » Tue Jun 21, 2011 9:18 am

I coudn't help but jump in here..... your plan doesn't make sense to me.
You're only talking about 7/8 of an inch. It would be SO much easier just to steam the whole piece and bend it into shape. It'll still be plenty strong, but without the mess and worry of glue. Why complicate things?

gaff · Post by **gaff** » Tue Jun 21, 2011 10:09 am

t3

I could do one piece but I already have the strips on hand to steam and lay up.

Steve

t3 · Post by t3 » Wed Jun 22, 2011 6:59 am

Okay, fair enough.......just seems like an unnecessary step, thats all.