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Looking for some advice about how to drill a hole into pink foam and not have it become oversized and way out of round.

 

I need to "plant" some 1/4" round posts into the pink foam that is the base for my layout. I prefer them to be relativly straight and upright. Every time I have tried to drill into the foam or any other foam for that matter the hole just becomes a total disater. The hole becomes oversied and out of round. Should I treat it like a piece of wood and start very small and increase in steps untill the final diameter is reached? I am also considering leaving the hole a bit undersized so that the dowel will have a "force fit" diameter to go into.

 

While I am asking questions, here is another. What is the best adhesive to use to glue these in?

 

As usual, Thanks for the advice folks.

Ken

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You need hard tubing or pipe that has the outside diameter of the size hole you want.  Cut it about 2 inches longer then the depth of your foam, and put some type of handle on it or wrap it with duct tape until you get a ball that fits your hand.  Plunge it thru the foam and pull the plug out.  Keep a drywall screw handy to pull the plug out of the tool.

 

Gene

Well I believe your over engineering this. It is a very simple situation really. Use any pointed object slightly undersized to the size of the wood post. A suitable sized nail for example, and simply push it in straight, pull it out and push your wood pole in...no adhesive required since the foam will hold it just fine. No real need to drill foam for any scenic application such as posts and trees etc. I've done this a zillion times...it works!

 

Bob

As Bob said, "poke and push" is good enough for most scenic elements.

 

But, sometimes you have a situation where more strength and precision is needed, such as in installing switch machines, tall light poles, or catenary.

 

In those situations, you can first carve out a square of foam and glue a small block of wood flush with the surface of the foam. You can then drill or screw into the wood block for extra support.

 

Jim

Ken,

 

Along the lines of what Gene suggested - - - and I have done this countless times with great success and not just for trains .

 

Buy a Ø1/4" brass tube at the hobby shop. They usually come in 12" lengths. You can cut it to about 4" long, or leave it full length.

 

With a small round file, file the inside edge of one end of the tube all the way around so that the end is sharp and the outer diameter or edge remains the original 1/4".

 

You can put something over the other end so it is easier to push but don't make this 'handle' too permanent.

 

With your hand, push while turning the tube through the foam.

 

Or, you can leave the non-cutting end bare and use your drill to drive the tube through the foam.

 

After a few cuts, and depending on how deep the holes are, the pink slugs will accumulate inside the tube, and you will need to use a smaller diameter rod to dislodge them.

 

BTW, for cutting larger diameter holes in a similar fashion, I cut small teeth along the cutting edge with a small triangular file.

 

Good luck!

 

Alex

Ken,  When I have drilled holes in our pink foam, that cover's our entire layout, I use the size of bit you need and twist it by hand. No drill needed.  Just turn the bit into the foam with lite pressure, dont punch it through or you could end up with a blow out on the bottom side.  This is what I have done for trees, posts, bolts to fasten down Fastrack to the foam, ect.  If gluing the pink foam we use loctite powergrab.  We have used this for gluing foam on foam, foam on the table frame and wood or metal.  Hope this helps.    Nick

Wow...you folks never cease to amaze me in regards to the range of ideas and knowledge that gets offered up as suggestions! Harry I am not sure where you came up with the Cork Brush idea but thats one I am sure nobody would have come up with! Same with the brass tube Alex. After I posted this last night I thought of my Pippi foam cutter. I have spare wires that are provided so that one can make custom cutters. I could bend one to just under a 1/4" "gap" and just insert, spin, and pull out the "plug".

 

Thanks for everyones help!

Ken

we have a guy in our club who insists on removing all his trees after each show on his module. He has a piece of 1/4 white pipe glued to the trunk of each tree.Then  In the foam  he has another piece of white plastic pipe glued and inserted(without drilling) flush with the top of the foam so that all his trees can be removed and re inserted into a tight fit tube  and never loosens up or become crooked.Not sure if this would be helpful in what your trying to accomplish.  Just a hint if your are looking for something to do. 

Thanks for everyones suggestions. Last night I discovered that I was indeed able to drill the holes. I suspect it was because there is foam board glued to the surface that kept the drill stable. As an added plus the foam board added a lot of support and ridgidity (sp?) since the holes were slightly undersized. Tonight I will "resead" the fussion fiber and ground cover. Then plant some weeds and call it good.

 

Thanks again. You guys are the best.

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