Seeking advice on using parf guide system with an HPL top

[BradyS]

Good evening,

As the title suggests it, I am looking for some more knowleadgeable opinions regarding the parf guide system's compatibility with HPL boards. My assembly/router table will have a double-layer top, namely: the 'under' top - 12 mm mdf; the 'top' top - 12 mm black core HPL, something like this Duropal HPL Compact Pyroex, black core | Order a sample!

It would help me if any of you have actually used such material with the parf system. Mine is mk2 but i don't think this is relevant. What I'd like to know is if the HPL material wears off the 20 mm cutter much faster and how much faster is that. Living in another country makes it harder to get a replacement drill from Axminster. And resharpening it here is out of the question due to the precise nature of the system. There will be circa 130-140 holes.


Much appreciated,
Brad

 

[Britman]

I haven't used HPL so can't say how well the cutter would stand up to it. How does HPL cut with other tools?
There is a back up option of making a router jig with the parf system then routing the hole with flush bit. That does kind of defeat the purpose of having the parf system though.

Maybe fire of an email to Axminster, they may know.

I'd be interested in knowing how you get on.

 

[Distinterior]

HPL is really tough on TC cutters!!
The recommended cutting tools are PCD tipped (Poly Crystalline Diamond) and cost an arm & leg....
I have worked with HPL using TC tipped tools, but they blunt quickly and the prospect of drilling 130/140 x 20mm dia holes would not appeal to me!

I would not doubt that you may well need at least 5 x 20mm drill bits to complete the job.

 

[Spectric]

When you own the Parf guide system it is not that hard to make the tops, would it not be easier to use something other than a material like HPL ?

I look at my tops with the 20mm holes as consumables, knowing at some point in time I will just have to make some more and I have several tops that get used for cutting sheet goods and assembly work, not to mention one in the vertical on my woodrat and an apron on the workbench.

Having just had to cut cement board I can say a PCD blade in a circular saw made life easier but PCD blades or cutters will be expensive. What is your reasoning behing using the HPL ? There have been people round here that have used Valchromat for tops which may be an option.

 

[Sideways]

I have a mk1 parf guide and have machined trespa HPL sheet for workbench tops with tct saw and tct router. Both fine but HPL does blunt TCT faster than timber does and I think it will wear your drill bit out so I haven't tried this.
It wouldn't occur to me to use HPL for a worktop I want covered in dog holes. The main advantage of HPL in a workshop is potentially for wear resistant sliding, and for it's impervious properties.
So for a top full of holes, I'd use a good mdf or valchromat (which I think will wear the bit too, but not as fast). If you must, keep the HPL as smooth as possible and just drill a half dozen strategic holes to locate a fence and a saw track.
Lastly. HPL has a smooth surface that would be a pain in most uses. Hold anything down on it and that thing will potentially slide sideways because there isn't as much friction, even when clamped quite hard. For anything other than machine tool fences and router table tops it's not an ideal material. I wouldn't choose it as an assembly table top and I wouldn't choose it as a fancy festool MFT alternative where I want to hold something down on it and have that stay still while cutting.

 

[BradyS]

I thank you for all the input. Now for the explanation of my intentions - first, in my country materials like Compacmel are not available, same goes for MR MDF. Our market of boards is ******, you can find what sells and non-standard materials (which in the UK are pretty standard) might be available on order basis provided you purchase a whole pallet which costs thousands of EUR.

I'd be interested in knowing how you get on.

Will make a post out of the build as soon as I have all details worked out. It will have some pretty interesting features, the best in several 'worlds'. Or so I imagine it, remains to be seen if I can pull it through.

Below is a representation of my workbench, just to get an idea. Basically it is a workbench built according to some plans I purchased and with the top 'borrowed' from Hooked on Wood's 'Ultimate Workbench' Building your ultimate workbench

What is your reasoning behing using the HPL ?

It all started with me finding out that the top of the JessEm Mast-R-Lift Excel (which has been my dream setup for many years - until I decided to betray and switch to Incra), as well as other router table tops and some of the quality insert plates are made of HPL. I am in a difficult market and country striving to put together a workshop for the hobbyist aspiring woodworker in a place that doesn't have this concept. So my options are terribly limited. I've also burned through my budget buying tools and machines from the UK and other places of the world. This is just to give a bit of context, not complaining. I managed to get my paws on a few boards of 12mm HPL from second-hand office furniture. HPL is so expensive here that we have a flourishing market of used HPL furniture.

Long story short, I want to use HPL for the router section. It's a Triton TRA001 on the corresponding Incra Magnalock insert plate and I want to know it's sturdy and solid even if that bench section will have reinforcements below.
I thought (or better said didn't think it through) and acted on impulse buying HPL boards to cover the entire bench in the idea that I would get a solid and very flat surface. Because flatness is another issue here. Altough I bought quality boards from reputed sellers, nothing came flat. And I live in a low humidity area. The humidity in my shop is very low, too. I also got the boards very cheap, about £22/sq meter. Luckily I have this healthy habit of asking when I am not sure of something, hence I'm here asking you. Beyond the router section, I can use anything.

So for a top full of holes, I'd use a good mdf

And that leads me here - mdf. After all, the parf system is recommended for mdf. But what makes 'a good mdf'? As I said, no MR mdf here. We have something called '3D mdf' which they explained as being an mdf that leaves a finer finish after being machined. It's also very neat on both sides, I would say sanded although I believe it has a different finish. But it feels like having been sanded to #1200. And it leaves a perfect edge after being cut or routed. Other than that, there is Valchromat which I can only buy in full sheets and for this size it's the equivalent of hundreds of pounds.

And than there is the famous mdf expansion issue. Or so I've been told. Maybe you can advise me in this in a few words so I understand it better.

For anything other than machine tool fences and router table tops it's not an ideal material.

I'm now thinking of leaving the router section in 12 mm HPL + 12 mm ply. For the holes section I'd like to use the approach I'm using for the rest of my benches. Mdf or plywood underside covered with 8 mm Valchromat. Some advice here will be helpful as well.

Much appreciated, sirs!

 

[BradyS]

I forgot to add that I'd also want to try taking advantage of HPL's durability with the Microjig Matchfit system. Of course I wouldn't destroy that precious router bit in the HPL but use one (or several) 14-degrees cheap dovetail router bits combined with straight bits for the rough material removal.

Also, I will use Incra's LS Positioner and Joinery Fence with this workbench setup. Exactly like Hooked on Wood shows it in his bench build, with the LS Positioner fitted on an mdf drilled with the parf guide.

 

[Sideways]

Valchromat is very hard but a little brittle. Edges tend to chip so add a small chamfer after building. It is costly so I would not use for something i'll cut into all over, but nice for a top like Denis made.
My trespa HPL sheet is 12 or 15mm thick. It is much stiffer than MDF or ply. For the router table section I would consider using 2 thicknesses of 12mm HPL drilled though and bolted together using countersunk headed bolts. I would do this instead of one layer HPL one layer ply to maximise stiffness and resist sagging due to the weight of the router, even if I also reinforced underneath.
Beware. Despite it's stiffness, HPL can sag. I bought a 600mm long offcut of 30mm thick HPL with ideas of making a router table and was disappointed to find this was already bent. With a straightedge on the 600mm surface, I could put a 1mm feeler gauge between it and the table in the middle. It is useless as a table top and as I can't straighten it I'll just sit a bench grinder on it :-(

 

[BradyS]

so add a small chamfer after building

I'll add chamfers to all edges. Had no idea about the brittleness, thank you for the info. I like chamfers and understood their place in woodworking. It's easy to understand especially after a few neat cuts in sharp edges.

For the router table section I would consider using 2 thicknesses of 12mm HPL drilled though and bolted together using countersunk headed bolts

2 layers of HPL. Now how come I didn't think of that?
Great idea, appreciate it! However, shouldn't I also use glue? As I understand, contact glue works with HPL boards.

Beware. Despite it's stiffness, HPL can sag

As you can see to the left, the table structure has structural supports. That 'fin' to the left is actually a board that goes all the way to the bottom. The right part is the router part and will have 3 such supports in order to maximize flatness of the top and to prevent sagging or other deformation.

It is useless as a table top and as I can't straighten it I'll just sit a bench grinder on it

Can't you flatten it with a router (sled)/cnc? I imagine it's a handful but for the money you paid... At 30 mm it must have been costly.

Just a thought, I've read that HPL boards have limited resistance to heat. Maybe they can be straightened if exposed to heat, it's worth investigating.

 

[Sideways]

You could glue, but then you are totally committed, can't take it apart and repurpose it.
If you do, it needs to be a non creep glue, so epoxy or ??
Bolts should work well as the HPL is so hard it won't crush.

You are right that my piece could be flattened but then I lose the surface layer :-(

 

[Distinterior]

In one of its uses, as a kitchen worktop, HPL sheets are adhered to each other using 2 pack epoxy glue.

 

[BradyS]

it needs to be a non creep glue, so epoxy or ??

In one of its uses, as a kitchen worktop, HPL sheets are adhered to each other using 2 pack epoxy glue.

I can use 2-part epoxy glue if you say that is the route. My other option was an adhesive that is widely available here and is listed as specifically for boards like HPL, Formica, this one, what do you think?
Bison | Product

You could glue, but then you are totally committed, can't take it apart and repurpose it.

I guess I'm totally committed after I make the cutout for the router insert plate. The way I thought it was to use it this way for good, no point in repurposing it. There is only one change I would do in the future and that is to replace the current incra magnalock plate and Triton router with an Incra router lift with a dedicated motor but this is totally out of the budget for now.

but then I lose the surface layer :-(

The way I see it is loosing a bit of the surface layer but gaining useability, as compared to now being a hi-tech paperweight. But I also agree, you have a point. As far as I remember, HPL can have it's surface re-finished by treatment with some of the woordworking oils if I remember correctly. I also think I saw some foil you can apply to the surface in order to renew it, maybe melamine foil, not sure. I read a lot about this on British websites - the info here is scarce, most people have no idea what HPL is.

 

[bp122]

I made mine out of HPL using the parf guide mk.1

Made a few mistakes
1. Didn't clamp the jog very well, so the holes are out in certain places (defeated the point of it in some places, really)

2. The top hole is always clean, if you have hpl on the bottom as well, the exit holes tear the HPL locally (not a clean break) so if you want it to be pristine above and below, I suggest doing the exercise twice with just over half the depth each time so you get clean holes.

3. Mk.II will be much better than mk.1, just clamp your jigs and the rules securely.

4. I made the holes with the top in situ, this is not the right way in my experience especially with HPL. put it on some raised scrap prices sof wood on the floor so you can ensure you are drilling vertically down and no sidewards force is exerted.

5. Mine was 25mm mrmdf with HPL on both sides, the experience may be different for you.

 

[Distinterior]

Ooopppss!

 

[Distinterior]

"I can use 2-part epoxy glue if you say that is the route. My other option was an adhesive that is widely available here and is listed as specifically for boards like HPL, Formica, this one, what do you think?"

I think that type of contact adhesive you linked to is suitable for sticking thinner HPL ( such as, if you were going to stick a sheet of 0.8mm/1.0mm thick material to MDF or plywood.)

If I were to try and adhere two faces together on 12mm thick material such as mentioned previously, I would abrade both faces, clean with DNA and then stick them together with the two pack epoxy.

 

[BradyS]

I would abrade both faces

How would you do that? Plain sanding or there migh be another way?

I made mine out of HPL using the parf guide mk.1

Thank you. Hands on experience always helps. I am now worried about ruining the drill bits, especially the 20mm one from the parf. I'll probably stick with using mdf/Valchromat in the mft section and keeping the HPL just on the router side. Sideways' idea of gluing two layers together will give me the extra durability. I'll still want to try making some Microjig Matchfit jigs out of HPL, I'm soooo curious how is that going to turn out. I've got some leftover straight cutters which are totally expandable and I'll try them here in small passes. Basically this is why I had this idea of using HPL for the parf holes - I was thinking of combining the holes with Matchfit channels for their clamps.

After I receive the top materials and I prime and varnish the structure, I'll create a distinct post on the build in the appropriate section. I'm adding some features to this table and there are things I looked online but didn't relly find, so the information will probably be helpful to some. Plus all your input which I'm grateful for, thank you.

 

[Distinterior]

How would you do that? Plain sanding or there migh be another way?

Just a random orbital sander with something like 80 or 120 grit paper......Enough to take the sheen off both faces to give the epoxy the best surfaces to bond to.

 

[bp122]

I'll still want to try making some Microjig Matchfit jigs out of HPL, I'm soooo curious how is that going to turn out. I've got some leftover straight cutters which are totally expandable and I'll try them here in small passes. Basically this is why I had this idea of using HPL for the parf holes - I was thinking of combining the holes with Matchfit channels for their clamps.

I did the same. Made some mistakes.

Top tip would be to constrain the router fully, leaving just one degree of freedom (don't just use one long fence and just rely on the pressure against it, that's where I went wrong). I cut the first channel very carefully, then 3d printed a jig to use the existing grooves to cut the rest.

 

[Christopher Souza]

You could glue, but then you are totally committed, can't take it apart and repurpose it.
If you do, it needs to be a non creep glue, so epoxy or ??
Bolts should work well as the HPL is so hard it won't crush.

You are right that my piece could be flattened but then I lose the surface layer :-(

Just buy MDF....HPL is not the material for an MFT top.
Here's a supplier in Romania: https://m.okorder.com/gl_Romania/MDF-Board/

 

[Spectric]

so if you want it to be pristine above and below, I suggest doing the exercise twice with just over half the depth each time so you get clean holes.

You could ensure that you have a backing board to avoid tearout, but when drilling the 3mm holes you will need to also drill the backing board as the 20mm boring bit needs that hole. Drilling the holes from both directions will just increase errors and probably not give nice clean holes in which the dogs fit snug.