# Laminate Seaming Router Bit



## JIMMIEM (Apr 4, 2010)

I will be making some laminate counter tops and will need to seam some of them. I will be making a laminate seaming jig which uses a bearing guided router bit to do this. I'm wondering if there is any particular bit to use for this process or will any bearing guide bit do it?


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## Cherryville Chuck (Sep 28, 2010)

Jim what do you mean by seaming jig?


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## JIMMIEM (Apr 4, 2010)

Cherryville Chuck said:


> Jim what do you mean by seaming jig?


When you make a laminate countertop that cannot be made out of 1 piece of laminate and requires that 1 or more pieces be used to create the top these individual pieces must be cut so that they abut each other with a nice tight joint i.e. seam. There are several techniques that can be used but the bottom line is that the pieces are butted together and cut at the same time to make mirror cut lines on the abutting pieces. After this seam cut is made the pieces can be glued to the substrate and the joint/seam will be supposedly barely noticeable. The seaming jig is used to hold the edges of the 2 pieces tightly together. The jig has a groove directly below the abutted edges. The router rests on the laminate and the bit's bearing rides along an edge of the groove to guide it and ensure that the router runs in a straight line to create mirror edges.


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## Cherryville Chuck (Sep 28, 2010)

Okay just making sure. Use a straight bit or maybe a down spiral. You also need connectors and you'll have to mill the pockets for them to set in. I like to add boards across under the seam and screw up from both sides to keep the joint flat. Make sure you use something waterproof in the joint. I've seen where water migrated into the joint and swelled up the particle board below.


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## JIMMIEM (Apr 4, 2010)

Cherryville Chuck said:


> Okay just making sure. Use a straight bit or maybe a down spiral. You also need connectors and you'll have to mill the pockets for them to set in. I like to add boards across under the seam and screw up from both sides to keep the joint flat. Make sure you use something waterproof in the joint. I've seen where water migrated into the joint and swelled up the particle board below.


I bought a book on making plastic laminate countertops and the author shows and describes the seaming jig he made. I've seen several references to his jig and folks seem to like it. Is your water reference to the jig or the actual countertop? The jig will be made from MDF and I'll make sure it is kept dry. I'll probably use plywood for the counter top substrate.....no water issue and I don't really like working with MDF due to the dust and dulling affect on bits and blades. I had a kitchen dishwasher leak which landed on my MDF router table in the basement below. The router table top was protected by its polyurethane finish. The fence swelled when the water hit it and I had to rebuild it.


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## Cherryville Chuck (Sep 28, 2010)

The water reference was to the counter top. You could see and feel where it swelled. Be careful using plywood. It isn't necessarily the difference in cost why it isn't used commercially, it's the flatness. Plywood can also swell up when wet and at the edge is the most likely place for it to happen. Also plywood is more likely to warp than mdc or particle board and does so with more force. I've never used ply so maybe there are other members who have who can respond with their experiences.


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## CharleyL (Feb 28, 2009)

I have a seaming base for my DeWalt Laminate trimmer. It has a slot in the side for the laminate to be trimmed, and you guide the opposite side of the base against to laminate that you want to join to. A router bit inside the base trims off the correct amount of the laminate in the slot to fit against the already attached laminate, *IF* the base is adjusted correctly. DeWalt seems to have discontinued their laminate trimmers, as I can't find a listing for them. I don't use my laminate trimmer much, but I don't know what I would do without one. My kit has 4 bases, and is very versatile.

Charley


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## JIMMIEM (Apr 4, 2010)

Cherryville Chuck said:


> The water reference was to the counter top. You could see and feel where it swelled. Be careful using plywood. It isn't necessarily the difference in cost why it isn't used commercially, it's the flatness. Plywood can also swell up when wet and at the edge is the most likely place for it to happen. Also plywood is more likely to warp than mdc or particle board and does so with more force. I've never used ply so maybe there are other members who have who can respond with their experiences.


I see different opinions on what to use for a substrate. i.e. MDF, Particle Board, Plywood. Decisions, decisions. Also, some say put the seam in the sink area as there is less of a seam.....others say absolutely don't put a seam in the sink area. Lots of different opinions.


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## Herb Stoops (Aug 28, 2012)

I have seen it all these ways and even in the center of the substrate where just the laminate butts. Done that myself many times in long office counter tops. Of course in "U" shaped counter tops the substrate and the laminate are butted together. We didn't have spiral bits in those days, so can't comment in those, but we used 1/2" diam. straight bits. As far as joining laminate at the center of the sink ,that was SOP at one time , but later it was laid all one piece. We didn't have MDF either it was all plywood A-B sanded and later particle board. That was when plywood had no voids, not like the stuff today. 

Herb


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## Cherryville Chuck (Sep 28, 2010)

Jim you can order laminate to 10 feet long for sure and I think maybe 12'. This can eliminate joints in most cases except where you turn 45*. One thing you should not do is try to turn a corner with a solid piece. It will crack across the turn over time. At corners like that you have to make a 45* joint. Although at the centre of the sink may be a logical point to make a join, it is also the wettest place you can make it. When I built my daughter's counter top we researched the difference in cost between using 4 x 8 and 5 x 10 and the square footage costs were close to the same. This gives you more options.


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## DaninVan (Jan 1, 2012)

I've removed a load of flat app. laminate from plywood counters over the years. They were fine, as Herb suggested, except for around sinks. 
In those days (the 50's and 60's ) I think all sinks were bedded in plumbers putty, which deteriorated with constant exposure to cleaning products and detergent, from the edge in.
It was pretty rare to find an installation where the cutout had been sealed with anything prior to the sink going in. 
Having said that, a lot of those counters had been in for 30 years+/-.


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## JIMMIEM (Apr 4, 2010)

Cherryville Chuck said:


> Jim you can order laminate to 10 feet long for sure and I think maybe 12'. This can eliminate joints in most cases except where you turn 45*. One thing you should not do is try to turn a corner with a solid piece. It will crack across the turn over time. At corners like that you have to make a 45* joint. Although at the centre of the sink may be a logical point to make a join, it is also the wettest place you can make it. When I built my daughter's counter top we researched the difference in cost between using 4 x 8 and 5 x 10 and the square footage costs were close to the same. This gives you more options.


Thank you for the tips. I do have a run of just under 12 feet so that may do the trick. A peninsula hangs off the long run so I will have to have a seam somewhere. If somebody manufactured a 6' X 12' sheet I could do it with no seams.


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## Cherryville Chuck (Sep 28, 2010)

Just remember not to use a solid piece going around a corner. I've seen it tried a few times, probably to avoid having to make a 45 and every one I've ever seen cracked the laminate.


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## xthoms (May 24, 2016)

Cherryville Chuck said:


> Just remember not to use a solid piece going around a corner. I've seen it tried a few times, probably to avoid having to make a 45 and every one I've ever seen cracked the laminate.


Yea, very important point!


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## JIMMIEM (Apr 4, 2010)

How large a corner are you talking about. I have a U shaped counter top. One end has a peninsula that extends 4 feet off the main run. This will definitely not go around the corner. The other end has a peninsula that extends 1 foot off the main run. I was going to do this 1 footer without a seam i.e. go around the corner.
Bad idea? Probably not a big deal to seam it, especially if my seaming jig works well. I'm still thinking the whole thing through and deciding where to put the seam(s). This is my first laminating project. I have 2 or 3 other smaller counter areas that are straight...I'll do these first to get the hang of working with laminate.


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## Cherryville Chuck (Sep 28, 2010)

If you turn the corner without making a joint chances are it will crack. I can't ever remember seeing a case where it didn't. You can go straight through but this makes the edges harder to do. You wouldn't be able to use a router for the corner but it could be filed to a finish. Of course the 45 across the corner is the best but the idea of getting it to fit right can be intimidating.


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## JIMMIEM (Apr 4, 2010)

Cherryville Chuck said:


> If you turn the corner without making a joint chances are it will crack. I can't ever remember seeing a case where it didn't. You can go straight through but this makes the edges harder to do. You wouldn't be able to use a router for the corner but it could be filed to a finish. Of course the 45 across the corner is the best but the idea of getting it to fit right can be intimidating.


I'll probably make straight seams and not try and do a 45 degree seam.


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## DesertRatTom (Jul 3, 2012)

Video of such a jig. Only thing I don't like is lack of a reference edge to assure that the cut is 90 to the reference edge. Simple jig using a trim router. I'd probably use knobs rather than butterfly nuts.


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## JIMMIEM (Apr 4, 2010)

DesertRatTom said:


> Video of such a jig. Only thing I don't like is lack of a reference edge to assure that the cut is 90 to the reference edge. Simple jig using a trim router. I'd probably use knobs rather than butterfly nuts.
> 
> https://www.youtube.com/watch?v=SsUBFkVbEKk


Thank You. The seaming jig in the book I bought isn't quite as elaborate as the one in the video but the principle is the same.


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## Cherryville Chuck (Sep 28, 2010)

You could also use it to do a 45 Jim. A 45 is an easy set up on that jig because the distance across the top is equal to the length you cut off from the end since a 45 is an isosceles triangle. Since few walls are straight and few corners are square, you use the splash board to cover the errors so if you're off by a small margin it shouldn't matter. You should be able to measure accurately enough to get it that close.


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## JIMMIEM (Apr 4, 2010)

Cherryville Chuck said:


> You could also use it to do a 45 Jim. A 45 is an easy set up on that jig because the distance across the top is equal to the length you cut off from the end since a 45 is an isosceles triangle. Since few walls are straight and few corners are square, you use the splash board to cover the errors so if you're off by a small margin it shouldn't matter. You should be able to measure accurately enough to get it that close.


Good to know. Thank You. I'm putting the jigs together, seaming and flush trimmer, and then it'll be own to doing the counter tops....along with a million other things on my wife's honey-do list.


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## Cherryville Chuck (Sep 28, 2010)

There's only two ways out from under the honey-do list, death or divorce.


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## JIMMIEM (Apr 4, 2010)

Cherryville Chuck said:


> There's only two ways out from under the honey-do list, death or divorce.


Hmmm....decisions, decisions. Gotta think this one over.


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## Herb Stoops (Aug 28, 2012)

Cherryville Chuck said:


> There's only two ways out from under the honey-do list, death or divorce.


Or you can put a round container under them and pull the pin when they are fulll and tack a new sheet up after they fall.

Herb


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## Stick486 (Jan 4, 2013)

JIMMIEM said:


> Hmmm....decisions, decisions. Gotta think this one over.


replace the honey...


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## JIMMIEM (Apr 4, 2010)

Stick486 said:


> replace the honey...


Easier said than done.


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## Stick486 (Jan 4, 2013)

then get her to share the load...


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## JIMMIEM (Apr 4, 2010)

Stick486 said:


> then get her to share the load...


You're kidding, right? When she says 'we' have to do this and 'we' have to do that I tell her that the only ones who should use the term 'we' are the Queen and somebody with a tape worm.....what you really you mean is 'I' have to do this and 'I' have to do that.


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## Stick486 (Jan 4, 2013)

I'm not kidding...
My wife rolled her sleeves up all the time of her own accord and there never was a job assignment list aka division of labor...
issues were rare...
maybe the two of us being good friends had a lot to do w/ it...


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## JIMMIEM (Apr 4, 2010)

Stick486 said:


> I'm not kidding...
> My wife rolled her sleeves up all the time of her own accord and there never was a job assignment list aka division of labor...
> issues were rare...
> maybe the two of us being good friends had a lot to do w/ it...


Does your wife have a twin sister that she could introduce me to?
My wife does her share and we do divide a lot of the work....she cooks and I clean, she picks the paint colors and I swing the brush, house fixit stuff, yard work, snow shoveling, and toilet cleaning are my domain.


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## Stick486 (Jan 4, 2013)

no sister...
no domains here....
now for the painting....
we picked the colors and somebody else painted....
we both cooked, cleaned, laundry and all the rest...
her and I replaced the septic....


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## Herb Stoops (Aug 28, 2012)

JIMMIEM said:


> Does your wife have a twin sister that she could introduce me to?
> My wife does her share and we do divide a lot of the work....she cooks and I clean, she picks the paint colors and I swing the brush, house fixit stuff, yard work, snow shoveling, and toilet cleaning are my domain.


Sounds like a full time job to me.

Herb


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## JIMMIEM (Apr 4, 2010)

Herb Stoops said:


> Sounds like a full time job to me.
> 
> Herb


And did I mention that I'm delegated to do this for my wife's 94 year old mother too? I don't really have to clean her toilet....just unplug it when the Miralax decides to work. Oh yes, we (that would be me) have to take her laundry to our house and wash it....then clean the dryer when her Poise Pad breaks and clogs everything up which requires 3 dry cycles instead of 1. Aren't you glad this discussion got started?


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## DaninVan (Jan 1, 2012)

"My wife does her share and we do divide a lot of the work..."
Same here; SWMBO finds the chores and I do them...maybe. 

The bonus to (my) _not_ doing them is, as they say, 'silence is golden'.


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## JIMMIEM (Apr 4, 2010)

DaninVan said:


> "My wife does her share and we do divide a lot of the work..."
> Same here; SWMBO finds the chores and I do them...maybe.
> 
> The bonus to (my) _not_ doing them is, as they say, 'silence is golden'.


Does this mean that you wear the pants but don't own them?


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## DesertRatTom (Jul 3, 2012)

A lot of good information in this thread. I learned a thing or two. Seems to me that making the jig to fit a laminate router's base would take up and slop in the cut. The idea of sealing the base ply around a sink opening with something waterproof never occurred to me. Thanks all. It is easy to forget that laminate is really just paper.


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