Jump to content

Recommended Posts

I have not had a huge amount of experience with MDF and I have had one or two surprises as I started my Speedy build with MDF keel and Bulkhead sections.

Not real problems so far but some unexpected aspects.

I would welcome any comments or hints on working with it.

 First it is softer than I expected and fairly fragile compared to the equivalent ply.

It seems to be "layered" and I was totally surprised when it sometimes split when drilled or worked - almost as if it had grain.

And when sanded  the surface goes "fluffy" where I am used to a "clean" sanding pass - am I using the wrong abrasive.

 

As I say  - no  actual problems so far but would welcome input on handling.

 

There are a couple of pics here     Working MDF  which illustrate my point

Link to post
Share on other sites

Use nice, sharp drill bits and work slowly and carefully.

 

MDF shouldn't delaminate, but it can split if you don't take care.

 

Try to pilot a hole before you nail it.

 

Try using good quality medium grit wet'n dry instead of glass/sand paper. A good quality aluminium oxide paper is also worth considering.

Link to post
Share on other sites

I have used MDF to make bulkheads for static (not swimming) models. the benefit of the material is that it is softer than plywood, so fairing is much easier. And it is also easier to saw with a scroll saw or bandsaw.

Another nice material for bulkheads is balsa plywood. It is produced in different thicknesses, 8...10 mm is best for this purpose.

Link to post
Share on other sites

Good Morning Everyone;

 

One important point to keep in mind with MDF is that the cheapest variety is not at all water-resistant, and will swell up in thickness in a damp atmosphere. Also, as mentioned above when cut it will 'fluff' up. If you use it by choice, there are several grades available, and it is best to use the most water-resistant variety, which has a green dye added to it so that the sheets have a greenish tinge (they look a bit sea-sick 🙂 )

 

This variety does not 'fluff' up when cut or sanded.

 

It is a material that has little strength to it, though, and I would tend to agree with YT about its suitability for modelling. And whatever you do, wear a mask when cutting or sanding the stuff, as the glue used is not good for intelligent life-forms.

 

All the best,

 

Mark P

Link to post
Share on other sites

It is weaker than birch plywood 4 times. Some aspects of MDF is very similar to a balsa wood. You should consider it as very soft wood or pile of sawdusts. Never use water on it. It will swell two or three times. I don't use it to fill bulkheads for the reason. (A balsa is better.) You will need enough waterproof varnish such as shellac. All the features of MDF say it is inadequate for serious model work.

 

An engineered wood is usually good for resource recycling, but the purpose of MDF is more suitable for big furniture.

 

Check the grade of emission rate of formaldehyde. The E2 is the cheapest and most widely used toxic panel. It emit the toxic for years. Not suitable for interior or furniture without varnish, paint, or coating film. The IKEA use E0 grade MDF. The Super-E0 grade is the best, but its cost is higher than conventional plywood.

Link to post
Share on other sites

MDF dust is quite nasty, very fine. It does not hold screws or nails very well. It does not glue well as the surface easily separates. absorbs water like crazy and long pieces can bend

 

Still, it is cheap and very flat. I use it for jigs, as scrap wood or to build things for limited time use  

Link to post
Share on other sites

Hi SpyGlass

 

I've not had the MDF problems you've experienced with my Speedy build, although I've not tried to drill it. As others have found, the bulkheads and other components are so precise they fit together with virtually no tweaking. As for sanding, I found ordinary sandpaper worked fine with no fluffiness - much easier to sand than ply - although of course a good mask is a wise precaution.

 

8 hours ago, Y.T. said:

MDF. I will never buy a kit with MDF. Business owners should realize. Customers will not swallow cheap crap

I would be interested to know what the kit designer and producer, Chris Watton, would make of this statement. Chris is one of the most experienced modellers and kit designers on the forum. 

 

Derek

Link to post
Share on other sites

I would guess that he (Chris) will just have to accept that YT will never buy one of his kits.... which is too bad as he (YT) is going to be missing out on some very fine examples of accuracy and quality in a kit. I am building Chris’s Revenge and it has MDF in it and it’s just fine, yeah it will split or break if you exceed the design parameters of the material but so will every other wood based medium. It just takes some adaptations of methodology to work with it. And the Revenge is years ago technology compared to Vanguard Models stuff - I don’t consider it a cheap cop out I think it allows laser cutting to be very accurate and the advantages far out weigh the drawbacks. It’s plenty strong for modeling purposes unless you have a habit of being ham fisted or impatiently aggressive and yeah, don’t soak it in water.... ?.?? 

Link to post
Share on other sites

Whilst ply tends to be a good, legacy material for many kits, it does suffer from some problems when it comes to the parts that make up the hidden core of a model. Firstly, it tends to warp because of the different absorption qualities of the layers used with the bonding materials/resins. Rarely do you ever get ply which is 100% straight, or remains so whilst sat in a box until a buyer builds his/her model.

 

Secondly, the tolerances of ply are extremely variable, even over short lengths. Those tolerances, even on thin ply, can be as much as 0.3-0.4mm ever the length of a part....perhaps even more when it comes to larger hulls. MDF's tolerance is far tighter and very consistent. 

 

That consistency means that a designer, such as Chris, can create a hull such as Victory, which has hundreds of interlocking joints, incorporating gun ports etc. I know that without this material, Chris could simply not have tackled a model with this approach, or you'd have been really hacked off with having to file out hundreds of joints because things weren't aligning properly, or the material was too thick or thin at whatever juncture...in relation to slots etc. 

 

Amati uses very high grade MDF for its kits, and this is the same grade as what Chris uses for his own projects. Of course, there are ways to work with it, as there are with any material. We use MDF at the school I work at, for kids GCSE projects, and it pins, screws, drills and glues with no problem, providing you work with the material and in accordance to its qualities. 

 

Here's some images of Amati's forthcoming Victory. 

 

Note no issues here.

 

Screenshot 2020-02-29 at 09.39.33.png

Screenshot 2020-02-29 at 09.39.18.png

Screenshot 2020-02-29 at 09.38.40.png

Screenshot 2020-02-29 at 09.38.24.png

Screenshot 2020-02-29 at 09.35.38.png

 

 

Link to post
Share on other sites

It is funny, when I was first told to try MDF over a decade ago when at Amati, I probably felt the same, and said the same as Y.T. I am sure I have said the same on here all those years ago. Since then, I realised just how much better this material is compared to the ply, which has so loose a tolerance for thickness between batches, it is only really good for the most base of hull framing. It is because of the tight thickness tolerance of MDF that allowed me try different methods of hull construction. Again, I have written this ad-nauseum on this forum.

 

A couple of weeks ago, I did make an investment in both cheaper poplar ply (the kind of ply in a lot of European kits) and the more expensive birch ply. The 3mm poplar ply was all actually 2.7mm thick, and the bulkhead tabs broke as soon as I tried to fit the 0.8mm birch ply deck, and the birch 3mm ply was actually well over 3mm thick. These variations are no good. You see, that would be a disaster for a model like Victory, as there are literally hundreds upon hundreds of interlocking parts which rely on a constant thickness. If one batch of ply was a different thickness to the last, the parts would either be way too sloppy or way too tight.

 

It is not a question of being 'cheap', it is a question of using the most appropriate material for the designs. Once I realised just how much better MDF is to work with, I changed my mind, and since the last decade, I have used it for literally dozens of kits and prototype models, including Victory. I have never had an issue with it, and most certainly had no issue sanding or with strength - I know it is stronger than the poplar ply you find in a lot of kits. If people still think, after all of these years, that this material is used because of cost, they are wrong, ply is simply too unreliable for thickness and flatness, more so for the more complex designs.

 

ETA - I have added a couple of pics of a hull which used the 3mm (in reality 2.7mm) poplar ply. It cuts very quickly, so much cheaper running costs than using MDF, which is a more dense material, and looks very nice, presentation wise, I can see why most manufacturers use it. However, note the missing bulkhead tabs on the hull pi, after I tried to fit the ply deck. I also had this issue years ago, when building the large Panart Victory and Sergal Sovereign of the Seas, it was a matter of course that some bits wouldn't make past certain building stages. I would have posted pics of the birch 3mm ply hull sample, but I couldn't even laser cut this as the height from the laser bed varied up to 20mm, it was so warped, meaning the laser would not focus properly. If it were cut, I am sure most would not want a keel shaped like a banana..

Poplar laser cut sample 2.jpg

Poplar laser cut sample.jpg

Link to post
Share on other sites

Oh dear - I wasnt seeking to criticise the use of MDF per se.

I just found that it couldnt  be treated in the same way as ply.

I dont like ply much in some applications - I hate when the ply edge shows in some kits. And I have so many warped ply keel sheets !!

 

But i think I wont have many problems  - they main thing I have gleaned is that  may be using the wrong abrasive sheet.

 

And AHHHHGGG just thought as I write this if its not very water resistant then my normal method of soaking planking strips and shaping them by leaving to dry clamped on hull may cause an issue.

 

A kind person has just reminded my that a bit of cling film bewtween strip and bulkhead protects the MDF but doesnt affect the shape of the strip to any extent

Link to post
Share on other sites
15 hours ago, Y.T. said:

MDF. I will never buy a kit with MDF. Business owners should realize. Customers will not swallow cheap crap. Today there are options. 

I think that’s a bit of a presumptive statement.  I’ve built a lot of nice, and expensive models that used MDF for keel and bulkhead. I like working with it more than ply. I think MDF is the better product, either will have adverse reaction to soaking, I’d be more concerned about ply delaminating and parts not fitting together due to warping than any MDF issues.  It most certainly isn’t cheap and thanks to MDF more parts can be lasered accurately. 

Link to post
Share on other sites
2 hours ago, glbarlow said:

I think that’s a bit of a presumptive statement.  I’ve built a lot of nice, and expensive models that used MDF for keel and bulkhead. I like working with it more than ply. I think MDF is the better product, either will have adverse reaction to soaking, I’d be more concerned about ply delaminating and parts not fitting together due to warping than any MDF issues.  It most certainly isn’t cheap and thanks to MDF more parts can be lasered accurately. 

 

...this ☝️

Link to post
Share on other sites
2 hours ago, glbarlow said:

I think that’s a bit of a presumptive statement.  I’ve built a lot of nice, and expensive models that used MDF for keel and bulkhead. I like working with it more than ply. I think MDF is the better product, either will have adverse reaction to soaking, I’d be more concerned about ply delaminating and parts not fitting together due to warping than any MDF issues.  It most certainly isn’t cheap and thanks to MDF more parts can be lasered accurately. 

I have attached pic showing the first planking complete on one of two of my beginners kits I am developing right now. I do lay the first limewood planking when it is still damp, never had an issue, and trust me, I have done dozens of models using the same method and base materials.

 

Talking of 'Cheap Crap', there is no MDF exposed on this pic (except perhaps the sacrificial bulkhead tabs above deck level that can just be made out. The rest of the laser cut parts are from solid pear wood, 21 individually cut laser pieces are shown that make up the pearwood upper bulwark pattern (with timberhead positions laser engraved to the inner sides, so no need more marking out), prow, keel and stern post parts with rabbets, and rudder. The first planking is limewood. All of this is glued to the MDF (low chemical, cleaner MDF suitable for laser cutting, and about the same price per sheet as the poplar ply some manufactures use - see my post above for the results of using that). Second planking will be in pear wood also, I could get away with using 'cheap crap' for a beginners kit, but I don't think that would be right. I will continue to use MDF for structural parts, as it is the best material for the job. If something better comes along, or tolerance levels and less warping is dealt with for ply, even the most expensive types, is addressed. As a modeller myself, I always hated either filing out every single slot or packing them before I can even fit the parts together. I always work on the assumption that if I hate certain aspects, quite a few others would too.

zulu with rudder.JPG

Link to post
Share on other sites

As always, if things don't work, it is rarely the fault of the material as such, it is usually a case of using the wrong material or the wrong quality of a particular type of material for the wrong purpose, or using the wrong tools, fasteners, adhesives, etc.

 

I quite like MDF for bread-and-butter construction, because of the precise dimensions of the material. Being homogenic, almost isotropic and composed of short fibres, there are few if any issues with warping or direction-dependent workability. I am getting high-quality MDF from supply-houses that cater for architectural model builders.

 

As the material has almost paper-like quality in some respect and a major problem is indeed water, which makes it swell. My models don't come into contact with water, but I had problems with architectural items, e.g. (false) door-frames that are made from MDF: a minor flooding in the kitchen destroyed the lower part of a door frame.

Link to post
Share on other sites

I think all this is more a reaction to change, it seems in every endeavor there is an element of resistance to moving away from the status quo, and usually, the reason for change is always suspect. Eventually, the change becomes the new norm and we can’t even remember why we ever did things the way we used to. 

Link to post
Share on other sites

An alternative to MDF is hardboard.  Hardboard is produced using a different method from MDF or HDF and the result is a hard, dense material.  Most hardboard found in big box stores has one smooth side and one textured side but it can be found with two smooth sides.  Often used as a substrate for painting it is very stable.  The down side is that it is very difficult to find in any thickness other than 1/8" but it can be laminated.  Just as with any manufactured material there are different grades.  The best grades can be found in art supply stores.  If anyone has used it for modeling it would be good to hear what your results were.

Link to post
Share on other sites

The key seems to be the quality of the MDF.  I've seen some that pathetic indeed and others were quite nice.  The stuff we buy at the local home improvement store, I wouldn't touch it.  I've also seen some at the local hobby shop that was quite good.  Each material seems to have it's own set of issues.   Just my $0.02

Link to post
Share on other sites

Looking at all the posts above, it is obviously a matter of personal preference, which is all quite normal. Both materials seem to work for some modellers, in some situations. Sometimes one might be more suitable than the other, but that really seems to be down to each individual's experience. 

 

Don't be too hard on poor Spyglass: as he said, he was not condemning MDF, merely seeking advice on how it might be treated differently from plywood, as he was discovering that it does not work in the same way. He was not advocating ply in preference to MDF at all.

 

All the best,

 

Mark P

 

 

Link to post
Share on other sites
2 hours ago, Mark P said:

Don't be too hard on poor Spyglass

I don't think anyone was being hard on SpyGlass - there might be another member I was reacting to though...  Personal choice is fine, this forum is great for celebrating deviations with personal choice.  Just don't condemn the choices of others.

Link to post
Share on other sites

 Who is being hard on me - My Admiral can beat your Admiral anyday !

 But its is true I was simply seeking guidance when I met with some unexpected features of MDF compared to ply which I am familiar with.

But on the other hand I am also finding some surprising  things out about working with solid wood - pear and holly  for example for example compared to ply

But I dont ever condemn any material or approach or say things are right or wrong - but i do like to pass on what works for me and what doesnt and I so welcome advice when I have nooo idea about something.

 

That said I do have some personal firmly held opinions FOR ME

I dont do CA -I hate ply edges showing - I dont like planks ending on the edges of planks ...........

 

 

Link to post
Share on other sites

@chris watton: do you have a recommendation for a particular supplier of MDF in the UK, or at least a type? There seems to be a huge range of suppliers as well as a largish range of MDF types. Looking online, it is hard to know the difference apart from statements such as 'high quality', 'moisture resistant'  and with a range of densities.

 

Tony

Link to post
Share on other sites
1 hour ago, tkay11 said:

@chris watton: do you have a recommendation for a particular supplier of MDF in the UK, or at least a type? There seems to be a huge range of suppliers as well as a largish range of MDF types. Looking online, it is hard to know the difference apart from statements such as 'high quality', 'moisture resistant'  and with a range of densities.

 

Tony

Like plywood, for laser cutting, it cannot be any MDF sheet, it needs to be laser compatible. Some glues and resins used in the manufacture of ply and MDF are not suited (outdoor use types, I think), so 'Laser Compatible' ply and MDF must be used, which are indoor types.

 

I did order a couple of sheets of 0.8mm ply that was a lot cheaper than what I was expecting. When laser cutting, I understood why, the laser burnt the glue, leaving the parts very blackened. I suspect the same would apply to certain varieties of MDF. I use 'Medite Premier MDF sheets'. I have bought sheets from Italy and the UK, there is no difference at all.

 

 

Link to post
Share on other sites
  • 3 weeks later...

I greatly preferred the MDF bulkheads in the Amati Pegasus kit over the plywood and basswood in other kits.  No flex and incredibly strong.  Be careful with the dust  and fumes though, especially if using power tools.  Really bothered my lungs when I was working on the Pegasus.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...