View Full Version : Project Underway
05-08-2005, 03:17 AM
I've begun installing the new ribs into my 17' center console. So far everything is going well. The steambox is working great. The new ribs are bending in nicely. I'm using #10 and #12 silicon bronze screws. The screws are larger than the ones that held the old ribs in as I'm using the screw holes from the previous ribs.
Question: Should I be applying silicon or some other sealer to the screw prior to driving it through the hull into the new rib? Currently I'm not applying anything to the screw. 10 ribs done 18 to go.
05-08-2005, 10:26 AM
Ya shouldn't even have silicon products in you shop if you are using paint or epoxy. Bee's wax or Akimpucky will help the screws to in easier.
Cullen T.M. McGough
05-08-2005, 10:58 AM
Boiled linseed oil is also a good lubricant. Eases the screw in while wet and forms a nice seal as it dries.
05-08-2005, 11:09 AM
cape cod wrote:
Should I be applying silicon or some other sealer to the screw prior to driving it through the hull into the new rib? I did a major undersides overhaul last year, which involved replanking and refastening (some 2500-3000 #10 bronze screws in all).
I rammed a benerous amount of Sikaflex down every hole with a steel rod, prior to driving in the new screw. This should help keep the water out of the screw hole, thereby preserving both screw and the adjoining wood.
BTW, it is nearly impossible to shove Sikaflex down a #10 hole using a standard issue dispenser gun and nozzle.
05-08-2005, 11:21 AM
Silicone doesn't like paint, among other faults and wouldn't be one of my choices.
I always seal a screw hole with something...red lead, linseed followed by varnish, white lead, epoxy, bedding compound or a combination of the above, usually red lead paint swabbed in the screw hole followed by bedding compound....depending on the application.
In plywood, I'm especially careful to seal those fragile and absorbant lam edges, either with epoxy under heat of double drilling the hole.
Gander at the deterioration around the screw holes among the derelicts in your local yards to see why.
In hard-use applications like this tiller yoke and thwart, I bed the entire hardware mortise in epoxy, to include the screw holes as has been described. Use paste wax as a release agent on the metal.
When fastening hardware plywood I double drill all the holes using epoxy as Frank describes...then use a bedding compound, too. I believe it a big mistake to rely on mild putty like common bedding compounds alone to seal something as critical as those absorbant and fragile lams.
Otherwise I use an industrial poly sealant similar to 4200. It's adhesive, but it lasts forever and doesn't leak. When applied between two painted surfaces it comes right off with a length of piano wire and no damage can occur beyond your layer of paint. Followup with a heat gun and a scraper and it comes right off with the paint. Course you gotta repaint....but I was gonna do that anyways.
Special applications like this CB pin get both a neoprene gasket and a tad of poly sealant.
And nail and drift holes should be swabbed with red lead paste before driving. Acts as a good lube, too, for those tight bronze drifts.
Here you see poly sealant and red lead used together to rivet a CB trunk.
Finally, some hardware I simply glue on in addition its fasteners using epoxy, if the installation is fragile and I want max strength. Heating the part up with a large soldering iron or torch easily releases the epoxy. Ever had a stem too sharp to make a brass nose strip for? Simply rasp a small flat and install narrow bronze flat stock using large brass box nails and epoxy.
[ 05-08-2005, 12:05 PM: Message edited by: Bob Smalser ]
05-08-2005, 11:43 AM
At the time, pgs 95-99 of "Wooden Boat Restoration" by Jim Trefethen were my guiding light.
Now, of course, you have the benefit of peering at the wider picture painted by Bob Smalser. ;)
05-08-2005, 04:10 PM
Thank you to all.
The 10 frames that I have already installed should I back the screws out and apply some type of bedding compound / red lead? Or just leave them as they are and treat the remaining holes associated with the 18 frames I have left to do.
I feel like I have a pretty strong bite into the wood. As I screwed into the oak it realy seemed to suck the rib into the plywood hull.
05-08-2005, 04:58 PM
Originally posted by cape cod:
...The 10 frames that I have already installed should I back the screws out and apply some type of bedding compound / red lead? ...
...I feel like I have a pretty strong bite into the wood. As I screwed into the oak it realy seemed to suck the rib into the plywood hull.
And I'd also make sure my clamping was adequate before driving screws....for the strongest possible (read undamaged) threads there shouldn't be any significant sucking noticed.
Crushed wood is quicker to rot.
Domesticated_Mr. Know It All
05-08-2005, 09:25 PM
Excellent Post Mr. Smalser. :cool:
Powered by vBulletin® Version 4.2.1 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.