Shaper Template

[John Grossbohlin]

I've made a fairly complex shaper template out of MDF and unlike many of the templates/jigs/fixtures that I make I think I?ll actually keep this one around... Since MDF is relatively soft and is prone to damage, and swells when it gets wet, I'm contemplating sealing it with something to both harden it and keep incidental moisture out of it.... I am curious to know what others have done... or don't bother to do with their "permanent" MDF patterns to keep them in working order for the long run?

As an aside, I never thought I'd see the day that I'd be using my various L-N spoke shaves on MDF but was delighted to find that they worked wonderfully for getting rid of the band saw marks and removing the waste to the line. This was done before smoothing the curves with with adhesive backed paper on thin strips of oak. It was kind of like discovering that a large L-N router is wonderful for getting dados to full depth after running wavy sheet goods over a dado blade on the table saw. Who would have thought that "old fashioned" tools would work so well with "modern" materials?!

John

[Lew Hodgett]

---------------------------------------------------------- More of a dust cover than a hardening agent, I use about a

1/2 lb - 1 lb cut of shellac, applied with a 2" chip brush.

Since there is so much alcohol in the cut, coats penetrate deeply and dry quickly so that several coats can be applied at one sitting.

BTW, keeps surfaces clean and finger print free.

Lew

[John Grossbohlin]

----------------------------------------------------------

Shellac is one of the possibilities I have in mind... Thanks for reinforcing this thought!

I was also thinking about poly, or taking it outside and coating it with CA glue... trying to find a balance between adequate and good and not go too far!

John

[Lew Hodgett]

---------------------------------------------- "John Grossbohl> Shellac is one of the possibilities I have in mind... Thanks for

---------------------------------------------- Uh ho, thinking again

Lew

[Swingman]

IME, damage through frequent use is likely to be a bigger problem than storage in a dry location, even in this humid Gulf Coast climate.

I keep them to the point it has become a storage problem, and most don't have any type of finish. Some are ten to fifteen years old and haven't suffered any noticeable effects of age. Even those stored outside, behind the shop, and in a large plastic outdoor storage bin.

The few that I've bothered to put a finish on, it has been with 3lb cut shellac, brushed on right of the can.

[Leon]

You might consider, for future templates, the green colored water resistant MDF. I have seen pieces of it submerged in a bird bath over night with no ill effects.

[John Grossbohlin]

Haven't run across that... Truth be told, the MDF I use for things like this comes out of the cull bin at Home Depot. It's often cut into 2x4 or 4x4 pieces and corners may be busted off but I don't care... It's cheap (typically $1-2) and I'm cutting it into small pieces anyway! It's not the material cost I'm trying to save it's my time...

This latest pattern consumed about two hours between layout, bandsawing and fairing. If I were a production shop I'd probably have it cut out of aluminum so it would hold up to repeated use... I anticipate using it again over the coming years and making the actual part from starting with rough cut wood through glue up, pattern cutting on the bandsaw and pattern shaping, to putting the final finish on will take less time than making a new pattern!

John

[John Grossbohlin]

You are probably correct here... it's just that after spending about two hours making the pattern it seems like it needs to be protected! Maybe I need one of those old map or blue print cabinets with the drawers for my plans and patterns! ;~)

John

[woodchucker]

I would mix up some titebond and water, not much water, just enough to make it spread a little. Then slather it on the ends. Sand, repeat.

Then use shellac to seal the whole thing.

I use tempered hardboard (masonite) for templates, because it is cheaper, I find it easier to work.. I use the 1/4, that can range from

3/16 to 1/4 :-(... sometimes I will glue two together.. I still like it better than mdf...

I like MDF for my work cart tops... solid, dead level... and seems to deaden sound pretty good.

[Morgans]

"woodchucker" wrote

BAD idea. Any titebond on the surface will get heated up when the pattern bit bearing rides over it, making it tacky again, and sticking in globs to the bearing, and you have a mess.

I love the CA glue idea, but that sounds expensive. The shellac idea should work, but best if kept thin. Epoxy thinned should work too. So should polly thinned.