Jump to content

The Bitumen Experiment


Recommended Posts

Hi Group,

 

I've been playing around with my typical finish -3 Coats Pure Tung Oil (first one cut 50 percent by mineral spirits) and I've added Bitumen to the top coat and here are the results - thanks to Dimitry on the Russian forums for giving me this tip to age wood.  No simulated caulking added here - just wood sanded to 600 and then finish applied

 

This is the finish I will apply to my next build - La Jacinthe in 1/36th.  Ive added some photos to compare this new technique to my usual on Confederacy.  

 

Your thoughts as always are appreciated,

Chris

 

 

post-1070-0-44141900-1410539383_thumb.jpg

post-1070-0-42936500-1410539409_thumb.jpg

Edited by ChrisLBren
Link to comment
Share on other sites

The Russians introduced ourselves to the ‘’bitume de judée’’.  The first time I saw it was on the French forum. Alex talked about his receipe containing the following ingredients.

 

Beeswax: Slows drying time, soften the color  and more transparent.  Mixing it with the

               bitumen    allows beewax molecules to bind  and make the asphalt more neutral

paraffin: help beewax or could be white wax candle

asphalt:   Was used by the egyptians for embalming   Oil soluble

pine resin:  Gives plastic properties  and can form a varnish if mixed with alchool

natural soap:  probably for the oils in the soap

turpentine:  Fluidity  and solubility of the mix

siccative:   shorter drying time, max 10% of total mix.

 

An easier version can effectively be done by mixing tung oil and bitumen. Depending of the bitumen solubility, an agent can be added to help to incorporate with tung oil. As long as bitumen is not applied in a too thick coat, there will be no problem to dry.

 

On the picture, concentrating on the first  3 tops ones, bare wood, tung oil, bitumen. Another way to apply it is with beewax + turpentine odorless to give it some flexibility and ease in application and add bitumen and then some polishing is needed (but this method is better suited for wood cabinet).  Wax is easy to apply on large surface. but when too many corners, it is a less interesting option.

post-184-0-03427500-1410608657_thumb.jpg

Edited by Gaetan Bordeleau
Link to comment
Share on other sites

I assume you are referring to Mr Shevelev,the ageing on his 74 looks the business.Incidentally his 74 took a silver at Haydock Park IMBS in the UK this summer(second only to another Russian entry)

 

Kind Regards

 

Nigel

 

I live near Haydock and I forgot about this show. Such a pity. I know you posted the date earlier in the year here.

Do you know of any pictures that were taken?

Link to comment
Share on other sites

Mitchel - this thread is about finishes not shows.  JerseyCity - i bought this Bitumen thru Ebay UK -not sure if its avail in the US. Gaetan your expert advice/input is always appreciated !

 

And Nigel - yes you are spot on -  Dimitry's  74 model and his advice are my influence on this finish. The Bitumen works as a wash.   Just a few kinks to work out - but I'm close.....

Link to comment
Share on other sites

Thanks Nigel - to get on my soap box - I feel that finish and carvings make a ship model.  The one thing i learned very well on Confederacy - is to thin your first coat of oil 50/50 with spirits which will set you up for a uniform finish (as oil does not penetrate a hard wood like Pear uniformly).  I learned this thru trial and error.   There are many things I'd love to do over with Confederacy (one being not relying on Chucks resin carvings for the human figures on my stern !) - but thats another story - (a #11 Exacto and some courage - anyone can carve with enough persistence.) 

 

I'm formulating a very distinct approach on the next model - thats why I've picked a simple but beautiful schooner as a test bed for my ideas.  As a novice oil painter - a Sepia wash actually might do the same thing as Bitumen - its worth a test to compare the results.

 

Stay tuned,

Chris

Link to comment
Share on other sites

Chris, I would not  do carving with  an exacto, in fact I do not use anymore this kind of blade.

I use almost exclusively sclalpel 5A with a handle, blue plastic covered and blade 11.

When you use scalpel, you find that an exacto does not cut.

 

Peaple say that scalpel blades breaks too easily. In fact, it is true, but when you  learn that this kind of blade is not made to be use in torsion, then you rarely breaks it.

 

Also, carving is a strange world, hand are made to do carving and feel shapes. Of course you need to practice, but when you try an you see what you can achieve, then a little miracle happens, you beleive that you can do it, and then you carve it.

Link to comment
Share on other sites

Guys - I wouldnt use bitumen if I was you its simply not uv stable, I realise its in small amouts but the thinner the bitumen film the shorter life it will have. Bitumen needs to be protected from surface oxidation. In commercial applications this can be very relevant. I am a former bitumen chemist with a stack of text on the subject based on data published by Shell. In a thin film application it can reduce to dust with light esposure, grades are usually a straight PEN grade typically represented by the numbers 25 to 300 or an oxidised Grade based on two numbers such as 95/25 these numbers relfect the test reults in simple mechincal tests used in industry.

 

Norman

Link to comment
Share on other sites

Norman,

 

I am surely not an expert about bitumen, but here is how I use it. About UV stability, I do not think that it does matter simply because models are intended to see the sun. The key is the quantity, effectively, too small quantity, it will not be enough apparent and too thick it will not dry. Usually bitumen is applied mainly on the hull, on large surface.  Bee wax is added in the mixture, so oxidation, I guess, is  not acting that much.

Bee wax has been used for centuries for wood cabinetry. In this case bitumen is added to this mixture to simulate time aging and I like the effect.

Link to comment
Share on other sites

  • 4 weeks later...

Chris, thanks very much for sharing your info on this post.  I agree 100% that what distinguishes the really amazing models out there from the very good is the finish and decorations (at least that's my relatively novice opinion).  I'm testing out some of these techniques on my Pegasus and Lyme using stains and oils for woods, and plan to test out undercoats/washes/dry-brushing highlights and lowlights onto the decorative pieces - eventually, I'll try carving.  I saw that folks in Europe were using bitumen, and I've always been curious as to what it is, how it is applied, etc.

 

Hope you're getting some sleep these days.  My twins are a year and a half now, and I feel like we've finally turned the corner.

Link to comment
Share on other sites

Greetings Chris,

 

With all due respect, I think the finish process you described is a lot of work and, in my opinion, not worth the effort. Painting departments in a Home Depot, Lowe's, Ace, hobby shops, etc. would have any number of finishes that look exactly like yours which can be applied in one go. I just don't understand why builders go through such machinations to reinvent a finish that paint companies have already perfected for our use. Granted, in other countries availability of materials may not be as it is here in the USA. If that is the case, builders have no other choice than to mix up their own concoctions. Other than that, mixing up special stuff seems to be a waste of time.

 

wq3296 

Link to comment
Share on other sites

W..

 

I did experiments with bitumen and i will try to explain what I observed. The main reason to use it is for properties  to make the wood look like older, to give more aging to the wood. This cannot be compare to paint because it does not cover completely. It would be more on the side of dyes. One of the advantage of this powder, is depending of the amount  you add, you will get different results. Asphalt can be mixed with many components depending of the look we want to produce.

 

Beeswax  Slows drying time, soften the color  and more transparent.  Mixing it with the

               bitumen    allows beewax molecules to bind  and make the asphalt more neutral

paraffin: help beewax or could be white wax candle

asphalt:   Was used by the egyptiens for embalming   Oil suluble

 

pine resin:  Gives plastic properties  and can form a varnish if mixed with alcool

natural soap:  probably for the oils in the soap

turpentine:  Fluidity  and solubility of the mix

siccative:   shorter drying time, max 10% of total mix.

 

 

My preference is to mix it with tung oil, that I prefer to other oils. When dry, this oil does not produce a shiny finish which is particuliary visible when you use a flash on the camera. At first, I used only tung oil which gives a look of 50 years in aging the wood. Later I did experiment by adding asphalt.

 

In small quantities, it will act as a dye but  clearer, not as dark as a dye can go. In the mixing, when you exceed his property of absorption by dilution, asphalt  powder will precipitate in the bottom  of the container and if you use this mix, it will produce on the wood a general finish plus different spots which can look like dirt caused by time.

 

I remember the first time I saw the utilisation of bitumen. It was on a 74 gun ship made by A French named Fichant. By using bitumen, he made his model look like 150 years older than it really was.

Edited by Gaetan Bordeleau
Link to comment
Share on other sites

No pics of your finish/model wq3296?  

 

Great post Gaetan - thanks for the scientific info - I know the Fichant's model - its gorgeous and looks 200 years old.  

 

As to the mix Steve - there are different ways to apply it Gaeten mixes his with Tung Oil.  I'm sure he can help you with the ratios.

 

I learned from  Dimitry Shevelev  mix Bitumen patina 50/50 with mineral spirits and apply to finished and fully cured pure Tung Oil (at least two coats) - it sort of acts like a wash in oil painting - and wipe off the excess.  

 

Here's an example of his work (i think he learned this technique from Fichant.

 

http://www.shipmodels.com.ua/eng/models/elite/74_gun_ship/

 

Hope this helps,

Chris

Link to comment
Share on other sites

Captain Steve,

 

What is pleasant with these mixes, everyone can create a mix which suits his needs. I do not follow any ratios. I add bitumen till I am satisfied with the result on a test piece of wood.

 

In this case, 3 ingredients are involved; bitumen, tung oil and turpentine.

Bitumen and tung oil can be mixed together but it is easier if turpentine is used first to help to dissolve the bitumen.

 

Bitumen can be applied with or without the tung oil together or separately. Again,  testing is the answer.

 

When possible, I prefer 1 coat of tung oil. I have never tried by example 10 coats, but I suspect that there woul be a kind of brilliant finish with a certain thickness. Also I think that this finish could be  reflective to the camera flash. I prefer the look of 1 coat, because it has a more natural look without this plastic finish. This reflective surface was particuliary true with linseed oil teck oil which, I guess, are not as refine.

 

Chris,

 

when you say that it sort of acts like a wash in oil painting  this is true especially for the first coat but not so  true for the second coat depending of the drying tie between the 2 coats.

Link to comment
Share on other sites

Hey Gaetan 

 

For me the trick of applying pure tung is to cut the first coat 50/50 with mineral spirits and then apply a second coat at full strength 24 hours later.  I found that the thinned first coat insured even absorption of the second coat.  Also much less seepage which is a tendency of pure tung. 

 

I am using Bitumen patina (which is a liquid) sold by art stores in Europe.  It sounds like you are using the solid form of Bitumen.  As far as the bitumen mix I've only used one coat thinned 50/50 with spirits after the tung is fully cured (a few days later) and it did go on like a wash.  I haven't attempted a second bitumen coat - I'm sure the ageing effect would be more pronounced.  

 

I am curious to see how the effect would change if mixed it directly in the tung oil instead of used as a top coat.  Ill have to try that one !

Chris

Edited by ChrisLBren
Link to comment
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.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...